IMAGE  EVALUATION 
TEST  TARGET  (MT-3) 


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Photographic 

Sciences 
Corporation 


23  WEST  MAIN  STREET 

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CIHM/ICMH 

Microfiche 

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CIHM/ICMH 
Collection  de 
microfiches. 


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Institut  Canadian  de  microreproductions  historiques 


1980 


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n 


D 


n 


n 


n 


Coloured  covers/ 
Couverture  de  couleur 


I      I    Covers  damaged/ 


Couverture  endommagie 

Covers  restored  and/or  laminated/ 
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I      I    Cover  title  missing/ 


Le  titre  de  couverture  manque 


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D 

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Pages  wholly  or  partially  obscured  by  errata 
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obtenir  la  meilleure  image  possible. 


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Additional  comments:/ 
Commentaires  suppldmentaires: 


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Ce  document  est  filmi  au  taux  de  reduction  Endiqu^  ci-dessous. 


10X 


14X 


18X 


22X 


26X 


30X 


y 

12X 


16X 


20X 


24X 


28X 


32X 


Tho  copy  filmed  here  has  been  raproducad  thanks 
to  tha  ganarosity  off: 

Douglas  Library 
Quaan's  Univarsity 


L'axamplaira  ffiimA  ffut  raprodiMt  grAca  A  la 
gAnirositA  da: 

Douglas  Library 
Quaan's  University 


The  images  appearing  here  are  the  best  quality 
possible  considering  the  condition  and  legibility 
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filming  contract  speciffications. 


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beginning  with  the  ffront  cover  and  ending  on 
the  last  page  with  a  printed  or  illustrated  impres- 
sion, or  the  back  cover  when  appropriate.  All 
other  original  copies  are  ffilmed  beginning  on  the 
ffirst  page  with  a  printed  or  illustrated  Impres- 
sion, and  ending  on  the  last  page  with  a  printed 
or  illustrated  impression. 


The  last  recorded  fframe  on  each  microfiche 
shall  contain  the  symbol  — *>  (meaning  "CON- 
TINUED"), or  the  symbol  V  (meaning  "END"), 
whichever  applies. 

Maps,  plates,  charts,  etc.,  may  be  filmed  at 
different  reduction  ratios.  Those  too  large  to  be 
entirely  included  in  one  exposure  are  filmed 
beginning  in  the  upper  left  hand  corner,  left  to 
right  and  top  to  bottom,  as  many  frames  as 
required.  The  following  diagrams  illustrate  the 
method: 


Lea  images  suivantes  ont  AtA  raproduites  avac  la 
plus  grand  soin.  compta  tenu  de  la  condition  at 
da  la  nattet*  de  I'exemplaira  film*,  et  en 
confformit6  avac  las  conditions  du  contrat  da 
ffilmage. 

Lea  exemplairas  originaux  dont  la  couvarture  en 
papier  est  ImprimAe  sont  filmte  en  commenpant 
par  la  premier  plat  at  en  terminant  soit  par  la 
darnlAre  page  qui  comporte  une  empreinte 
d'impression  ou  d'illustration,  soit  par  la  second 
plat,  salon  la  cas.  Tous  las  autras  exemplairas 
originaux  sont  filmte  en  commen^ant  par  la 
premiere  page  qui  comporte  une  empreinte 
d'impression  ou  d'illustration  at  en  terminant  par 
la  darniire  page  qui  comporte  une  telle 
empreinte. 

Un  des  symboies  suivants  apparaftra  sur  la 
derniire  image  de  cheque  microfiche,  selon  le 
cas:  le  symbols  -^^  signifie  "A  SUIVRE",  le 
symbols  V  signifie  "FIN". 

Les  cartes,  planches,  tableaux,  etc.,  peuvent  dtre 
filmAs  A  des  taux  da  rdduction  diffirents. 
Lorsque  le  document  est  trop  grand  pour  fttre 
raproduit  an  un  seul  clichA,  il  est  film*  A  partir 
de  Tangle  supArieur  gauche,  de  gauche  d  droits, 
et  de  haut  en  bas,  en  prenant  la  nombre 
d'images  n6cassaire.  Les  diagrammes  suivants 
illustrant  la  mithoda. 


1 

2 

3 

1 

2 

3 

4 

5 

6 

P  I  A  S.  h  3 


A  HALF-CENTURY  OF  SCIENCE. 

BvT.  H.  HUXLEY,  F.  R.  S. 

AND  GRANT  ALLEN. 


I.  THE  ADVANCE  OF  SCIENCE 
IN  THE  LAST  HALF  CENT- 
URY. 

BY  T.  H.  HUXLEY.  F.R.S. 

The  most  obvious  and  the  most  db- 
tinclive  features  of  the  history  of 
civilization,  during  the  last  fifty  years, 
is  the  wonderful  increase  of  industrial 
production  by  the  application  of  ma- 
chinery, the  improve'.nent  of  old  tech- 
nical processes  and  the  invention  of 
new  ones,  accompanied  by  an  even 
more  remarkable  development  of  old 
and  new  means  of  locomotion  and  in- 
tercommunication. By  ihis  rapid  and 
vast  multiplication  of  the  commodities 
and  conveniences  of  existence,  the 
general  standard  of  comfort  has  been 
raised  ;  the  ravages  of  pestilence  and 
famine  have  been  checked;  and  the 
natural  obstacles,  which  time  and 
space  offer  to  mutual  intercourse,  have 
been  reduced  in  a  manner  and  to  an 
extent,  unknown  to  former  ages.  Tlie 
duninution  or  removal  of  local  igno- 
rance and  prejudice,  the  creation  of 
common  interests  among  the  most 
widely  separated  peoples,  and  the 
strengthening  of  the  forces  of  the 
organization  of  the  commonwealth 
.igainst  those  of  political  or  social 
anarchy,  thus  effected,  have  exerted 
an  influence  on  the  present  and 
future  fortunes  of  mankind  the  full 
significance  of  which  may  be  divined, 
b'.!t  cannot,  as  yet,  be  estimated  at  its 
f  ill  value. 

This  revolution — for  it  is  nothing 


less — in  the  political  and  social  as- 
pects of  modern  civilization  has  been 
preceded,  accompanied,  and  in  great 
measure  caused,  by  a  less  obvious,  but 
no  less  marvelous,  increase  of^ natural 
knowledge,  and  especially  of  that  part 
of  it  which  is  known  as  physical 
science,  in  consequence  of  the  appli- 
cation of  scientific  method  to  the  inves- 
tigation of  the  phenomena  of  the  ma- 
terial  world.  Not  that  the  growth  of 
physical  science  is  an  exclusive  prerog- 
ative of  the  Victorian  age.  Its  present 
strength  and  volume  merely  indicate 
the  highest  level  of  a  stream  which 
took  its  rise,  alongside  of  the  primal 
founts  of  philosophy,  literature,  and 
art,  in  ancient  Greece ;  and,  after 
being  dammed  up  for  a  thousand  years, 
once  more  began  to  flow  three  cent- 
uries ago. 

It  may  be  doubted  if  even-handed 
justice,  as  free  from  fulsome  panegy- 
ric as  from  captious  depreciation,,  has 
ever  yet  been  dealt  out  to  the  sages  of 
antiquity  who,  for  eight  centuries, 
from  the  time  of  Thales  to  that  of 
Galen,  toiled  at  the  foundations  of 
])hysical  science.  But,  without  enter- 
ing into  the  discussion  of  that  large 
question,  it  is  certain  that  the  labors 
of  these  early  workers  in  the  field  of 
natural  knowledge  were  brought  to  a 
standstill  by  the  decay  and  disruption 
of  the  Roman  Empire,  the  consequent 
disorganization  of  society,  and  the 
diversion  of  men's  thoughts  from  sub- 
lunary matters  to  the  problems  of 
the  supernatural  world  suggested  by 
Christii^n  dogma  in  the  Middle  Ages. 


I 


'  '^56^5 


THE  ADVANCE  OF  SCIENCE 


And,  notwithstanding  sporadic  at- 
tempts to  recall  men  to  the  investiga- 
tion of  nature,  here  and  there,  it  was 
not  until  the  fifteenth  and  sixteenth 
centuries  that  physical  science  made 
a  new  start,    founding  itself,    at   first, 


with  Kepler's  great  additions ;  the 
astronomical  discoveries  and  the  phy- 
sical investigations  of  Galileo;  the 
mechanics  of  Stevinus  and  the  "  De 
Magnete  "  of  Gilbert ;  the  anatomy 
of  the    great    French      and     Italian 

altogether  upon  that  which  had  been  I  schools  and  the  physiology  of  Harvey. 

done  bv  the  Greeks.     Indeed,  it  must  j  In  Italy,  which  had  succeeded  Gieece 

in  the  hegemony  of  the  scieniitic 
world,  the  Accademia  dei  Lyncei  and 


be  admitted  that   the  men  of  the  Re 
naissance,    though    standmg  on    the 

philosophers, 
ihey  saw  as 
much  as  their  forerunners  had  done. 


shoulders  of 


the 


old 


were  a  long  time  before 


sundry  other  such  associations  for  the 
investigation  of  nature,  the  models  of 
all  subsequent  academies  and  scientific 


The  first  serious  attempts  to  carry'  societies,  had  been  founded  while  the 
further  the  unfinished  work  of  Archi-  j  literary  skill  and  biting  wit  of  Galileo 
medes,  llipparchus,  and   Ptolemy,  of :  had  made    the   great   scientiiic   ques- 


Aristoile     and    of 


enough 


arose  among  the 


Galen,  naturally  i 
astronomers 
and  the  physicians.  For  the  impen- ' 
ous  necessity  of  seeking  some  remedy 
for  the  physical  ills  of  life  had  in- 
sured the  preservation  of  more  or  less 
of  the  wisdom  of  Hippocrates  and  his 
successors ;  and,  by  a  happy  conjunc- 


intelligible, 
pub- 


general 


tions  of  the  day  not  only 
but   attractive,   to   the 
lie. 

In  our  own  country,  Francis  Bacon 
had  essayed  to  sum  up  the  past  of 
physical  science,  and  to  indicate  the 
path  which  it  must  follow  if  its  great 
destmies  were  to   be    fuifilletl.     And 


tion  of  circumstances,  the  Jewish  and  1  though  the  attempt  was  just  such  a 
the  Arabian  physicians  and  philoso- :  magnificent  failure  as  might  have  been 
l)hers  escaped  many  of  the  influences  j  expected  from  a  man  of  great  endow- 
which,  at  that  time,  blighted  natural  ments,  who  was  so  singularly  devoid 
knowledge  in  the  Christian  world,  j  of  scientific  insight  that  he  could  not 
On  the  other  hand,  the  superstitious  ;  undtTstand  the  value  of  the  work 
hopes  and  tears  which  afToided  conn-  already  achieved  by  the  true  instaur- 
tenance  to  astrology  and  to  alchemy  ators  of  physical  science  ;  yet  the 
also  sheltered  astronomy  and  the  majestic  eloquence  and  the  fervid 
germs  of  chemistry.    Whether  for  this,   vaticinations  of    one    who   was   con 


or  for  some  better  reason,  the  found- 
ers of  the  schools  of  the  Middle  Ages 
included  astronomy,  along  with  geome- 
try, arithmetic,  and  music,  as  one  of 
the  four  branches  of  advanced  educa- 
tion ;  and,  in  this  respect,  it  is  only 
just  to  them  to  observe  that  they 
were  far  in  advance  of  those  who  sit 
in  their  seats.  The  school-men  con- 
sidered no  one  to  be  properly  educated 
unless  he  were  acquainted  with,  at 
any  rate,  one  branch  of  physical  sci- 
ence. We  have  not,  even  yet,  reached 
that  stage  of  enlightenment. 

In  the  early  decades  of  the  seven- 
teenth century,  the  men  of  the  Re- 
naissance could  show  that  they  had  al- 
ready put  out  to  good  interest  the 
treasure  bequeathed  to  them  by  the 
Greeks.  They  had  produced  the  as- 
tronomical   system     of    Copernicus, 


spicuous  alike  by  the  greatness  of  his 
rise  and  the  depth  of  his  fall,  drew 
the  attention  of  .all  the  world  to  the 
"  new  birth  of  Time." 

But  it  is  not  easy  to  discover  satis- 
factory evidence  that  the  "  Novum 
Organum"had  any  direct  beneficial 
influence  on  the  advancement  of  nat- 
ural knowledge.  No  delusion  is 
greater  than  the  notion  that  method 
and  industry  can  make  up  for  lack  of 
motherwit,  either  in  science  or  in 
practical  life  ;  and  it  is  strange  that, 
with  his  knowledge  of  mankind,  Bacon 
should  have  dreamed  that  his,  or  any 
other,  "  via  inveniendi  scientias" 
would  "  level  men's  wits  "  and  leave 
little  scope  for  that  inborn  capacity 
which  is  called  genius.  As  a  matter 
of  fact,  Bacon's  "via"  has  proved 
hopelessly  impracticable ;  while  the 


ve 

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kn 


IN  THE   LAST   HALl-CENTURY. 


my 
las" 


"anticipation   of  nature"  by  the   in 
vcn'i  Ml   of  hypotheses  based   on    in 


Bacon  or  Ilobbes,   Rend  Descartes, 
not   only  in  his  immortal   "  JiiscGurs 


conriictc  inriiictions,  whicli  he  spe-  de  la  Methode  "  and  elsewhere,  went 
cially  c<  lulennis,  has  j^rovcd  itself  to  down  to  the  foundations  of  scientific 
be  a  most  crticient,  indeed  an  indis-  certainty,  bur,  in  his  '*  Principes  de 
pensa))le,  instnnnent  of  scientific  Philosophie,"  indicated  where  the 
pro:;ress.  l-'inally,  tliat  transceiuien- :  fjoal  of  physical  science  really  lay. 
tal  rili'lu-my — the  siipeiiii<liiceinent  of  [  However,  1  )Lfscartes  was  an  eminent 
new  forms  on  matter — wliicii  llacon  '  mathematician,  and  it  would  seem 
dt'cIaiL's  to  be  tlie  supreme  aim  of '  that  the  bent  of  his  mind  letl  him  to 
scieiKc,  has  been  whojiv   i_:;nored   by  i  overestimate    the  value  of  deductive 


reasoiiiiii;  from  general  ])rinciples,  as 
much  as  iJacoii  had  underestimated 
it.     Tlie  pro};ress  of  physieal  science 


those  who  have  created    the    physical 
kno'.vle<l;;e  of  the  present  day. 

Kven  the  eloquent  advocacy  of  the 
Chanrellor  broii<:;ht  no  unmixed  good  has  been  effected  neither  by  Haconians 
to  physical  science.  It  was  natural  iior  by  Cartesians,  as  sueli,  but  by 
enougli  tliat  the  man  who,  in  his  bet- ,  men  like  (lalileo  and  Harvi-y,  Hoyle 
ter  moments,  took  "all  knowledge  '  and  Newton,  who  would  have  done 
for  his  patrimony,"  but,  in  his  worse, ;  their  work  just  as  well  if  neiliier  15a- 
sold  tiiat  bir'.iiright  for  tlie  mess  of :  con  nor  Descartes  had  ever  pro- 
pottage  of  court  favor  and  pro- 'pounded  their  views  respecting  the 
fessional  success,  for  pomp  and  shosv,  manner  in  which  scientific  nivestiga- 
shoulcl  be  led  to  attach  an  undue  lion  should  bo  ])ursue(l. 
value  to  the  practical  advantages  The  progress  of  science,  durin*; 
which  he  foresaw,  as  Roger  1}. icon  I  the  first  century  aft<!r  Ikicon's  death, 
and,  indeed,  Seneca  had  foreseen,  j  by  no  means  veritied  his  sanguine 
long  before  his  time,  must  follow  in  '  prediction  of  the  fruits  which  it  would 
the  train  of  the  advancement  of  nat- 1  yield.  For,  though  the  revived  and 
uial  knowledge.  The  burden  of  I?a- j  renewed  study  of  nature  had  spread 
con's   pleadings   for    science    is    the  i  and   grown  to  an  extent  which   sur- 


passed reasonable  expectation,  the 
practical  results — the  "good  to  men's 
estate  " — weie,  at  tlrst,  by  no  means 
apparent.  Sixty  years  after  Bacon's 
death,  Newton  had  crowned  the  long 
labors  of  the  astronomers  and  the 
physicists,  by  co-ordinating  the   i)Iie- 


gathering  of  fruit  " — the  importance 
of  winning  solid  material  advantages 
bv  the  investigation  of  nature  and 
the  desirableness  of  limiting  the  ap- 
plication of  scientific  methods  of  in- 
(juiry  to  that  field. 

Bacon's  younger  contemporary, 
Hobbes,  casting  aside  the  prudent  nomena  of  molar  motion  throughout 
reserve  of  his  predecessor  in  regard  the  visible  universe  into  one  vast  sys- 
to  those  matters  about  which  the  tem  ;  but  the  "  Princi!)ia "  helped  no 
Oown  or  the  Church  might  have .  man  to  either  wealth  or  comfort, 
something  to  say,  extended  scientific ,  Descartes,  Newton,  and  Leibnitz  had 
methods  of  inquiry  to  the  phenomena  :  opened  up  new  worlds  to  the  ma'lie- 
of  mind  and  the  |.iroblems  of  social  I  matician,  but  the  acriuisitious  of  their 
organization;  while,  at  the  same  [genius  enriched  only  man's  ideal 
time,  he  indicated  the  bounflary  be- 1  estate.  Descartes  had  laid  the  foun- 
iween  the  province  of  real,  and  that  dations  of  rational  cosmogony  and  of 
of  imaginary,  knowledf"".  The  i  physiological  psychology ;  Boyle  had 
"  Principles  of  Philosophy  '  and  the  i  proilucetl  models   of  experimentation 


"  Leviathan  "  embody  .'i  coherent  sys- 
tem of  purely  scientific  thought  in 
language  which  is  a  model  of  clear 
and  vigorous  English  style.  At  the 
same  time,  in  France,  a  man  of  far 
greater  scientific  capacity  than  either 


in  various  branches  of  physics  and 
chemistry;  Pascal  and  Torricelli  had 
weighed  the  air ;  Malpighi  and  Grew, 
Ray  and  Willoughby  had  done  work 
of  no  less  importance  in  the  biologi- 
cal sciences  ;   but  weaving  and  spin- 


Tin:  AnvANCH  or  science 


n'lng  were  carried  on  with  the  old  ap- 

Cliaiiccs ;  nobody  could  travel  faster 
y  sea  or  by  land  than  at  any  previous 
time  in  the  world's  history,  and  King 
(leorge  could  send  a  message  from 
London  to  York  no  faster  tiian  King 
John  nught  have  done.  Metals  were 
worked  from  their  ores  by  immemo- 
rial rule  of  thumb,  and  the  center  of 
the  iron  trade  of  these  islands  was 
still  among  the  oak  forests  of  Sussex. 
The  utmost  skill  of  our  mechanicians 
did  not  get  beyond  the  production  of 
a  coarse  watch. 

The  middle  of  the  eighteenth  cent- 
ury is  illustrated  by  a  host  of  great 
names  in  science — English,  French, 
German,    and    Italian — especially    in 


subservient  to  their  wants,  and  which 
would  disappear  if  man's  shaping  >ind 
guiding  hand  were  withdrawn.  Kvery 
mechanical  artifice,  every  chemically 
pure  substance  employed  in  manu- 
facture, every  abnormally  fertile  race 
of  plants,  or  rapidly  growing  and  fat- 
tening breed  of  animals,  is  a  part  of 
the  new  nature  created  by  science. 
Without  it,  the  most  densely  popula- 
ted regions  of  modern  Europe  and 
America  must  retain  their  primitive, 
sparsely  inhabited,  agricultural  or 
pastoral  condition ,  it  is  the  founda- 
tion of  our  wealth  and  the  condition 
of  our  safety  from  submergence  by 
another  flood  of  barbarous  hordes  ;  it 
is  the  bond  which   unites  into  a  solid 


the  fields  of  chemistry,  geology,  and  |  political  whole,  regions  larger  than 
biology ;  but  this  deepening  and 
broadening  of  natural  knowledge  pro 
duced  next  to  no  immediate  prac- 
tical benefits.  Even  if,  at  this  time, 
Francis  Uacon  could  have  returned 
to  the  scene  of  his  greatness  and  of  i  luxuries,  but  conduce  to  physical  and 
his  littleness,  he  must  have  regarded  |  moral  well-being.  During  the  last 
the  philosophic  world    which  praised  i  fifty  years,    this  new  birth    of    time, 


any  empire  of  antiquity  ;  it  secures 
us  from  the  recurrence  of  the  pesti- 
lences and  famines  of  former  times  ; 
it  is  the  source  of  endless  comforts 
and  conveniences,  which  are  not  mere 


this  new  nature  begotten  by    science 
upon    fact,    has   pressed    itself    daily 


and  disregarded  his  precepts  with 
great  disfavor.  If  ghosts  are  consist- 
ent, he  would  have  said,  "These  land  hourly  upon  our  attention,  and 
people  are  all  wasting  their  time,  just }  has  worked  miracles  which  have  mod- 
as  Gilbert  and  Kepler  and  Galileo  ,  ified  the  whole  fashion  of  our  lives, 
and  my  worthy  jihysician  Harvey  did  |  What  wonder,  then,  if  these  aston- 
ii>  my  day,  VVhere  are  the  fruits  of  i  ishing  fruits  of  the  tree  of  knowledge 
the  restoration  of  science  which  1 1  are  too  often  regarded  by  both  friends 
promised?       This    accumulation     of '  and  enemies  as  the  be-all  and  end-all 


bare  knowledge  is  all  very  well,  but 
cui  bono  I  Not  one  of  these  people 
is  doing  what  I  told  him  specially  to 
do,  and  seeking  that  secret  of  the 
cause  of  fotms  which  will  enable  men 
to  deal,  at  will,  with  matter,  and  su- 
perinduce new  natures  upon  the  old 
foundations." 

l>ut,  a  little  later,  that  growth  of 
knowledge  beyond  imaginable  utili- 
tarian ends,  which  is  the  Condition 
precedent  of  its  practical  utility,  be- 
gan to  produce  some  effect  upon  prac- 
tical life  ;  and  the  operation  of  that 
part  of  nature  we  call  human  upon 
the  rest  began  to  create,  not  "'new 
natures,"  in  Bacon's  sense,  but  a  new. 
nature,  the  existence  of  which  is  de- 
pendent upon  men's  efTorts,  which  is 


of  science  ?  What  wonder  if  some 
eulc)gize,  and  others  revile,  the  new 
philosophy  for  its  utilitarian  ends  and 
its  merely  material  triumphs.^ 

In  truth,  the  new  philosophy  de- 
serves neither  the  praise  of  its  eulo- 
gists, nor  the  blame  of  its  slanderers. 
As  I  have  pointed  out,  its  disciples 
were  guided  by  no  search  after  prac- 
tical fruits,  during  the  great  period  of 
its  growth,  and  it  reached  adolescence 
without  being  stimulated  by  any  re- 
wards of  that  nature.  The  bare  enu- 
meration of  the  names  of  the  men 
who  were  the  great  lights  of  science 
in  the  latter  part  of  the  eighteenth 
and  the  first  decade  of  the  nineteenth 
century,  of  Herschel,  of  Laplace,  of 
Young,  of  Fresnel,  of  Oersted,  of  Cav- 


IN  THE  LAST  HALF-CENTURY. 


5 


riends 
end-all 
some 
le  new 
ids  and 

by   de- 
5  eulo- 
derers. 
isciples 
r  prac- 
eriod  of 
escence 
any  re- 
are  enii- 
ie   men 
science 
hteenlU 
leteenth 
lace,  of 
of  Cav- 


endish, of  Lavoisier,  of  Davy,  of  La- 
marck, of  Cuvier,  of  Jussieu,  of  De- 
candoUe,  of  Werner  and  of  Hntion, 
suffices  to  indicate  the  strength  of 
physical  science  in  the  aj;e  immedi- 
ately preceding  that  of  which  I  have 
to  treat.  But  of  which  of  these  gr^at 
men  can  it  be  said  that  their  labors 
were  directed  to  practical  ends  ?  I 
do  not  call  to  mind  even  an  invention 
of  practical  utility  which  we  owe  to 
any  of  them,  except  the  safety  lamp 
of  Davy.  Werner  certainly  paid  at- 
tention to  mining,  and  I  have  not  for- 
gotten James  Watt.  But,  though 
some  of  the  most  important  of  the 
improvements  by  which  Watt  con- 
verted the  steam-engine,  invented 
long  before  his  time,  into  the  obedi- 
ent slave  of  man,  were  suggested  and 
guided  by  his  acquaintance  with  sci- 
entific principles,  his  skill  as  a  prac- 
tical mechanician,  and  the  efficiency 
of  Bolton's  workmen  had  quite  as 
much  to  do  with  the  realization  of  his 
projects. 

In  fact,  the  history  of  physical 
science  teaches  (^and  we  cannot  loo 
carefully  take  the  lesson  to  heart) 
tliat  the  practical  advantages,  attain- 
able through  its  agency,  never  have 
been,  and  never  will  be,  sufficiently 
attractive  to  men  inspired  by  the  in- 
born genius  of  the  interpreter  of  na- 
ture, to  give  them  courage  to  under- 
go the  toils  and  make  the  sacrifices 
which  that  calling  requires  from  its 
votaries.  That  which  stirs  their 
puLses  is  the  love  of  knowledge  and 
tile  joy  of  the  discovery  of  the  causes 
of  things  sung  by  the  old  poets — the 
supreme  delight  of  extending  the 
realm  of  law  and  order  ever  farther 
towards  the  unattainable  goals  of  the 
infinitely  great  and  the  infinitely 
small,  between  which  our  little  race 
of  life  is  run.  In  the  course  of  this 
work,  the  physical  philosopher,  some- 
times intentionally,  much  more  often 
unintentionally,  lights  upon  some- 
thing which  proves  to  be  of  practical 
value.  Great  is  -  the  rejoicing  of 
those  who  are  benefited  thereby ; 
and,  for  the  moment,  science  is  the 
Diana   of   all   the  craftsmen.       But, 


I  even  while  the  cries  of  jubilation  re- , 
sound  and  this  floatsam  and   jetsam , 
:  of  the  tide    of  investigation    is  being 
turned    into   the  wages   of  workmen 
and  the  wealth  of  capitalists,  the  crest 
;  of  the  wave  of  scientilic  investigation 
is  far  away  on  its  course   over  tlic   il- 
^  limitable  ocean  of  the  unknown. 
j      Far  be  it  fiom  me  to  depreciate  the 
I  value  of  the  gifts  of  science  to  practi- 
cal life,  or  to  cast  a  doubt  upon  the 
'  propriety  of    the  course  of   action  of 
1  those  who  follow  science  i*n  the  hope 
j  of  finding  wealth  alongside  truth,  or 
,  even   wealth   alone.      Such  a  profes- 
sion is  as  respectable    as   any  other, 
j  And  quite  as  little  do  I   desire  to  ig- 
nore the   fact  that,  if  industry  owes  a 
[  heavy  debt   to   science,  it  has  largely 
I  repaid  the  loan  by  the  important  aid 
:  which  it  has,  in  its  turn,  rendered  to 
the  advancement  of  science.     In  con- 
'sidering   the   causes   which  hindered 
;  the  progress  of   physical   knowledge 
in  the  schools  of  Athens  and  of  Alex- 
landria,  it  has  often   struck  me  *  that 
where   the  Greeks  did  wonders   was 
in    just    those    branches  of  science, 
such    as    geometry,    astronomy,    and 
anatomy,   which    are    susceptible    of 
^  very  considerable  development   with- 
out any,  or  any  but  the  simplest,  ap- 
:  pliances.     It   is  a  curious  speculation 
j  to  think  what  would  have   become  of 
j  modern  physical  science  if  glass   and 
I  alcohol    had    not    been  easily  obtain- 
able ,  and   if   the  gradual  perfection 
{ of  mechanical  skill  for  industrial  ends 
had  not  enabled   investigators  to  ob- 
tain,   at    comparatively    little     cost, 
I  microsco|)es,   telescopes,  and   all   tiic 
exquisitely  delicate  apparatus  for  de- 
I  terminiiig    weight   and   measure    and 
for  estimating  the  lapse  of  lime    with 
exactness,  which  they  now  command. 
If  science  has  rendered    the   colossal 
development  of  modern  industry  pos- 
:  sible,   beyond   a   doubt    industry  has 
i  done  no  less  for  modern  physics  and 
]  chemistry,  and   for  a  great  deal   of 

•  There  are  excellent  remarks  to  the  same 
effect  in  Zeller's  Philosophic  Jer  Griechtn, 
'I'heil  n.  Abth.  ii.  p.  407,  and  in  Kncken's 
Die  Methode  der  Arislotelischen  Forschiinf^, 
[jp.  1 38  et  seq. 


THE   ADVANCE  OF  SCIENCE 


modern  biology.  And  as  the  cap- 1  science  has  ever  been  done  by  men, 
tains  of  indiisliy  have,  at  last,  begun  whatever  their  powers,  in  whom  the 
to   be   aware   that   the   condition   of  divine  afllatus  of  the  triithstei<er  was 


snccess  in  that  warfare,  under  the 
forms  of  peace,  which  is  Ivnown  as 
industrial   competition  Hes  in  the  dis- 


wanting.  Men  of  moderate  capacity 
have  done  great  things  because  it 
animated   tiiem  ;    aiifl    men    of   great 


ciplineof   tlie    troops  and  the  use  of  |  natural  gifts   have    failed,  aijsolutely 
arms  of    precision,  just  as  much  as  it   or    relatively,    because    they    lacked 


does  in  the  warfare  which    is   called 
war,  their  demand  for  that  discipline, 
which    is   technical    education,  is    re 
u|)on    science    in    a   manner 


acting 


this  one  thing  needful. 

To  anyone  who  knows  the  business 
of  investigation  practically,  liacon's 
notion  of  establishing  a  comjiany  of 
which  will,  assuredly,  stimulate  its' investigators  to  work  for  "  fruits,"  as 
future  growth  to  an  incalculable  ex-  if  the  pursuit  of  knowledge  were  a 
tent.  It  has  become  obvious  that  kind  of  mining  operation  and  only 
the  interests  of  science  and  of  in  !  required  well-directed  picks  and 
dustry  are  identical,  that  science  ]  shovels,  seenis  very  strange. f  In 
cannot  make  a  step  forward  without,  ■  science,  as  in  art,  and,  as  I  believe, 
sooner  or  later,  opening  up  new  chan- 1  in  every  other  sjjhere  of  human  activ- 


ncls  for   industry ;  and,  on    the  other 
hand,  that  every  advance  of   industry 


itv,  there  mav  be   v/isdom  in  a   nnilti- 
tude  of   counsellors,  but  it  is  only  in 


facilitates  those  experimental  investi- -  one  or  two  of  them.  And,  in  scien- 
gations,  upon  which  the  growth  of  |  tilic  inquiry,  at  any  rate,  it  is  to  that 
science  depends.  AVe  may  hope  one  or  two  that  we  must  look  for 
that,  at  last,  the  weary  misunder- ;  light  and  guidance.  Newton  said 
standing  between  the  practical  men  j  that  he  made  his  discoveries  by  "  in- 
who  professed  to  despise  science,  and  I  tending"  his  mind  on  the  sul^ject ; 
the  liigh  and  dry  philosophers  who  j  no  doubt  truly.  Hut  to  equal  his  suc- 
professed  to  despise  practical  results,  i  cess  one  must  have  the  mind  which 
is  at  an  end.  |  he    "  intended."      Forty   lesser   men 

Nevertheless,  that  which  is  true  of  |  might  have  intended  their  minds  till 
the  infancy  of  physical  science  in  the  i  they  cracked,  without  any  like  result. 
Greek  world,  that  which  is  true  of  its!  It  would  be  idle  either  to  affirm  or 
adolescence  in  the  seventeenth  and  to  deny  that  the  last  half-century  has 
eighteenth  centuries,  remains  true  of '  produced  men  of  science  of  the  (  ali- 
its  riper  age   in    these   latter   days  of   bre  of   Newton.     It  is  sufficient  that 

the    nineteenth  century.     The   great 

steps  in  its  progress  have  been  made,  "  For  a  long  time  that  sensiliility,  or  that 
are  made,  and  will  be  made,  bv  men  vanitv,  which  people  call  love  of  glory  is 
who  seek  knowledge  simply  because  much  blunted  in  me.  I  labor  much  less  to 
"  '    ■'  catch    the   suffrapcs   of   the    public   than  to 

obtain  an  inward  ajiproval  which  has  always 
been  the  mental  reward  of  mv efforts.    With- 


they  crave   for   it.      They  have   their 
weaknesses,  their   follies,  their   vani 
ties,  and  their  rivalries,  like  the    rest 


out  doubt   I    have  often  wanted  the  spur  of 


of   the   world  ;   but    whatever  by-ends    y^^'ty  »"  "^ite  me  to  pursue  my  researches 
,   '.        ,.      .  1    •  1    :  in  moments  of   disgust  and  discouragement. 

may   mar   their   dignity  and    impede  ;  ,j„j  .^„  j,,^.  eompliments  which  I  have  re- 

their   usefulness,    this   chief   end    re-  ccived  from  MM.  Ar.-igo,  De  Laplace,  or 
deems     them.*       Nothing     great     in    Hiot,  never  gave  me  so  much   pleasure  as 

the   discovery  of  a  theoretical   truth   or  the 

• "  ~~  confirmation    of    a    calculation    by  r.xperi- 

*  Fresnel,  after  a  brilliant  career  of  dis- '  ment." 
covery  in  some  of  the  most  difficult  regions';  t  "  Memor.ible  exemple  de  j'impuissance 
of  physico-mathematical  science,  died  at  ',  des  recherches  collectives  appliquees  i  la 
thirty-nine  veais  of  .ige.  The  following  pas-  deco'jvertc  dcs  verites  nouvelles  !  "  savs  one 
sage  of  a  letter  from  him  to  Vuung  (written  of  the  most  distinguished  of  living  French 
in  November  1824),  (jiiotcd  bv  Whewcll,  so  s.rT\nif.t.  n(  the  coriiorate  chemical  work  of 
aptly  illustrates  the  sjiirit  which  animates  the  old  Academie  dcs  Sciences.  (See  IJer- 
the  scientific  inquirer  that  I  may  cite  it :  i  thelot,  Science  ct  PhilosoJ'hi(,  p.  201.) 


IN  THE  LAST   HALF-CKNTUKV. 


said 


or  tliat 
glory  is 
h  less  to 
than  to 
s  always 
.    With- 
e  spur  of 
.■searches 
agciiKMil. 
have  re- 
place, or 
asure    as 
»   or  the 
experi- 

missance 
lees  5i   la 
savs  one 
Ig  I'"reiuh 

work  of 
ISee    licr- 


it  can  show  a  few  capacities  of  the 
first  rank,  competent  not  only  to  deal 
profiiaijiy  with  the  inheritance  be- 
qiu-alhed  by  their  scientific  fore- 
fatiiers,  but  to  pass  on  to  their  succes- 
sors physical  truths  of  a  hi;j;hcr  order 
than  any  yet  readied  by  the  human 
race.  And  if  they  have  succeeded  as 
Newton  succeeded,  it  is  because  they 
Iiave  sou'^iu  truth  as  he  soujjlit  it, 
with  no  other  object  than  the  finding 
it. 

I  am  conscious  tliat  in  undertaking; 
to  jjive  even  the  briefest  sketch  ot 
tile  pro<;ress  of  jihysical  science,  in 
all  its  branches,  (hirinj;  the  last  half- 
century,  I  may  be  thought  to  have 
exhibited  more  courage  than  discre- 
tion, and  perhaps  more  presrunption 
than  either.  So  far  as  physical 
science  is  concerned,  the  days  of 
Admirable  Crichtons  have  long  been 
over,  and  the  most  indefatigalile  of 
hard  workers  may  think  he  h  is  done 
Wfll  if  he  has  mastered  one  of  its 
minor  subdivisions.  Nevertheless,  it 
is  possible  for  anyone,  who  has  fa- 
miliarized himself  with  the  operations 
of  science  in  one  department,  to  com- 
prehend the  significance,  and  even  to 
form  a  general  estimate  of  the  value, 
of  the  achievements  of  specialists  in 
other  departments. 

Nor  is  there  any  lack  either  of  guid- 
ance, or  of  aids  to  ignorance,  Hy  a 
happy  chance,  the  first  ediiion  of 
Whewell's  "  Historv  of  the  Inductive 
Sciences"  was  published  in  1837,  and 
it  affords  a  very  useful  view  of  the 
state  of  things  at  the  commencement 
of  the  Victorian  epoch.  As  to  sub- 
sequent events,  there  are  numerous 
excellent  summaries  of  the  progress 
of  various  branches  of  science,  es- 
pecially up  to  1881,  which  was  the 
jubilee  year  of  the  British  Associa- 
tion.* And,  with  respect  to  the  bi- 
ological sciences,  with  some  parts  of 


•  I  am  jiarticularly  indebted  to  mv  friend 
and  colleague  I'rofcssor  Kiickcr,  K. U.S.,  for 
the  many  aiiite  criticisms  and  siii.'t;<..stions 
«)n  my  remarks  respectin^i  the  idtiniiitf  prob- 
lems of  ]ihysics.  with  which  he  has  favored 
nic,  and  by  which  1  have  greatly  profited. 


which  my  studies  have  familiarized 
me,  my  personal  experience  nearly 
coincides  with  the  preceding  half- 
century.  1  may  hope,  therefore,  that 
my  chance  of  esca|)ing  serious  errors 
is  as  gr)od  as  that  of  anyone  else,  who 
might  have  been  persuadfd  to  under- 
take the  somewhat  pfrilous  enterprise 
m  wliii'h  I  find  invstdf  engaged. 

There  is  yet  another  pn-fatory 
remark  which  it  seems  desirable  I 
should  make.  It  is  that  I  think  it 
proper  to  confine  myself  to  the  work 
done,  without  saying  anvihing  about 
the  doers  of  it.  Meddling  wiili  t|iu;s- 
tiuns  of  merit  and  priority  is  a  iliornv 
business  at  the  liest  of  times,  an«l 
unless  in  case  of  necessity,  altogether 
undesirable  when  one  is  dealing  wiih 
contemporaries.  No  such  nccis^ity 
lies  upon  ine  ;  and  I  shall,  llierefore, 
mention  no  names  of  living  men.  lest, 
perchance,  I  should  incur  tht;  reproof 
which  the  Israelites,  who  struggled 
with  one  another  in  the  tlcld,  ad- 
dressed to  Moses--"  Who  m.rde  thee 
a  prince  and  a  judge  over  us.'''' 

Physical  science  is  one  and  indivis- 
ible. Althoiii;h,  for  practic.il  pur- 
poses, it  is  convenient  to  mark  it  out 
into  the  primary  regions  of  physics, 
chemistry,  and  biologv.  and  to  sub- 
divide these  into  suliordinaie  prov- 
inces, yet  the  method  of  investigation 
and  tin:  ultimate  object  of  the  phys- 
ical inquirer  are  everywhere  the  same. 

'The  object  is  the  discovery  of  the 
rational  order  which  pervades  the 
universe  ;  the  method  consists  of 
observation  and  experiment  (which  is 
observation  under  artificial  condi- 
tions) for  the  determination  of  the 
facts  of  nature  ,  of  indiutive  and  de- 
ductive reasoning  for  the  fliscovery 
of  their  mutual  relations  and  connec- 
tion. The  various  bratiches  of  plivsi- 
cal  science  differ  in  the  extent  to 
which,  at  any  given  moment  of  their 
history,  observation  on  the  one  hand, 
or  ratiocination  on  the  other,  is  their 
more  obvious  feature,  but  in  no  other 
way;  and  nothitig  can  be  more  in- 
correct than  the  assninplion  one 
sometimes    meets    with,    that  physics 


THE   ADVANCE  OF  SCIENCE 


has  one  method,  chemistry  another, 
and  biology  a  third. 

All  physical  science  starts  from 
certain  postulates.  One  of  them  is 
the  objective  existence  of  a  m.lterial 
world.     It  is  assumed  that  the  phe- 


Physical  science  therefore  rests  on 
verified  or  uncontradicted  hypotheses; 
and,  such  being  the  case,  ir  is  not 
surprising  that  a  great  condition  of 
its  progress  has  been  the  invention  of 
veritable  hypotheses.     It  is  a  favorite 


nomena  which  are  comprehended  popular  delusion  that  the  scientilic 
under  this  name  h;ive  a  "substratum  "  |  incpiirer  is  imder  a  sort  of  moral  ob- 
of  *.'Xlended,  in»penetrable,  mobile  ;  ligation  to  abstain  from  going  beyond 
substance,  which  exhibits  the  (lualiiy  i  that  generalization  of  observed  facts 
known  as  inertia,  and  is  termed  mat- 1  whici'  is  absurdly  called  "  Haconian" 
ter.*  Another  postulate  is  the  uni- ;  induction.  Hut  any  one  who  is  prac- 
versality  of  the  lasvof  causation  ;  that ,  tically  acquainted  with  scientific  work 
nothing  iiappens  without  a  cause  (that  i  is  aware  that  those  who   refuse  to  go 


is,  a  necessary  precedent  condition), 
and  that  the  stale  of  the  physical  uni- 
terse,  ot  any  given  monient,  is  the 
consequence  of  its   state   at   any  pre- 


beyond  fact,  rarely  get  as  far  as  fact ; 
and  anyone  who  has  studied  the  his- 
tory of  science  knows  that  almost 
every  great  step  therein  has  been 
.Another  is  that  any!  made  by  the  "anticipation  of  nature," 
of  the  rules,  or  so-called  "laws  of  that  is,  by  the  invention  of  hypotheses, 
nature,"  by  which  the  relation  of  phe-  which,  though  veritable,  often  ha(I 
nomena  is  truly  defined,  is  true  for  all  very  little  foundation  to  start  with  ; 
time.      The  validity  of   these   postu- i  and,  not  unfrequently,   in   spite  of  a 


Ceding  monient 


long  career  of  usefulness,  turned  out 
to  be  wholly  erroneous  in  the  long 
run. 

The  geocentric  system  of  astron- 
omy, with  its  eccentrics  and  its  epicy- 
cles,   was   an    hypothesis   utterly   at 


lates  is   a   problem   of  metaphysics ; 

they  are  neither  self-evident  nor  are 

they,  strictly  Speaking,  flemonstrablc. 

The  jnstilkaiion  of  their em|)loyment, 

as  axioms  of  physical  phiiosophy,  lies 

in  the  circumstance  that  expectations 

logically  based  upon   them   are  veri  '  variance   with    fact,  which    neverthe- 

fied,  or,  at  any  rate,  not  contradicted,  I  less  did  great  things  for  the  advance- 
ment of  astronomical  knowledge. 
Kepler  was  the  wildest  of  guessers. 
Newton's  corpuscular  theory  of  light 
was  of  much  temporary  use  in  optics, 
though    nobodv   now    believes  in  it; 

challciH'.e.I.     It  nuy  be  said,  for  example,  |  j^,„i  t|,e  tmdulatory  iheorv,  which  has 

mat.  oil  the  livpothesi-*  of  lioscoviLh,  matter  i  j     i     .1  '1  .1 

has  no  extension.  ».ci..R   reduced  to   n.athe-  ^"If'^'^'^*^'-'^'     ^'^f     corpuscular    theory 

and  has  proved  one  of  the  most  fer- 
tile   of    instruments   of    research,  is 


whenever  they  can   be  tested  by  ex- 
perience. 

•  1  am  .iware  that  this  prnjiosition  mav  be 


niatical  points  serving  as  centers  of  "forces.' 

lint  as  the  "forces"  of   the  various  centers  !  tile    of     instruments 

are  conceived  to  limit  one  .inolhei's  action  I  jj^^ed  on  the   h\  pothesis  of  the  exist- 

m  such  a  manner  that   an  area  around  cacli  1  r  i^    .»        »i  .u  ..•  r 

center  has  .in  individnalitv  of  >ts  own.  exten-  ence  of  an  "ether,    the  properties  of 

siun  comes  back  in  the  'orm  of  that  area. 
Again,  a  very  eminent  mathematician  and 
])itysicist — the  late  Ckrk  Maxwell — has  de- 
clared that  impenetrability  is  not  essential  to 
our  notions  of  matter,  and  that  two  atoms 
m.iy  conceivably  occui)y  ^^'^  same  space.  I 
am  loth  to  dispute  any  dictum  of  a  philos- 
opher as  remarkable  for  the  subtlety  of  his 
intellect  as  for  his  vast  knowledge ;  but  the 
assertion  that  one  and  the  same  point  or  area 
of  space  can  have  different  (conceivably  op- 
posite) attributes  appears  to  me  to  violate 
the  principle  of  contradiction,  which  is  the 
foundation  not  only  of  i>hysical  science,  but 
of  logic  in  general.  It  means  that  A  can  be 
not-A. 


which  are  defined  m  propositions, 
some  of  which,  to  ordinary  appre- 
hension, seem  physical  antinomies. 

It  sounds  paradoxical  to  .say  that 
the  attainment  of  scientific  truth  has 
been  effected,  to  a  great  extent,  by 
the  help  of  scientific  errors.  liut  the 
subject-matter  of  physical  science  is 
furnished  by  observation,  which  can- 
not extend  beyond  the  limits  of  our 
faculties;  while,  even  within  those 
limits,  we  cannot  be  certain  that  any 
^^'ervation  is  absolutely  exact  and 


IN  THE   LAST  IIALF-CENTURY. 


astron- 
i  epicy- 
ily   at 
vertlie- 
vaiice- 
ledge, 
lessers. 
light 
optics, 
in  it ; 
ch  has 
theory 
ost  fer- 
rch,  is 
e  exist- 
rties  of 
sitions, 
appre- 
lies. 
ay  that 
th  has 
;nt,  by 
iut  the 
nee  is 
h  can- 
of  our 
those 
at  any 
t  and 


exhaustive.  Hence  it  follows  that 
any  given  generalization  from  ob- 
servation may  be  true,  within  the  lim- 
its of  our  powers  of  observation  at  a 
given  time,  and  yet  turn  out  to  be  un- 
true, when  those  powers  of  observa- 
tion are  directly  or  indirectly  en- 
larged. Or,  to  put  the  matter  u\  an- 
other way,  a  doctrine  which  is  untrue 
absohiiely,  may,  to  a  very  great  ex- 
tent, be  susceptible  of  an  interpreta- 
tion in  accordance  with  the  truth. 
At  a  certain  period  in  the  history  of 
astronomical  science,  the  assumption 
that  the  planets  move  in  circles  was 
true  enough  to  serve  the  purpose  of 
correlating  such  observalions  as  were 
then  possil)le ;  after  Kepler,  the  as- 
sumption that  they  move  in  ellipses 
became  true  enough  in  regard  to  the 
state  of  observational  astronomy  at 
that  time.  We  say  still  that  the  or- 
bits of  the  planets  are  ellipses,  be- 
cause, for  all  ordinary  purposes,  that 
is  a  sufficiently  near  approximation  to 
the  trutii;  but,  as  a  matter  of  fact, 
the  center  of  gravity  of  a  planet  de- 
scribes neither  an  ellipse  or  any  other 
simple  curve,  but  an  imntensely  com- 
plicated undidaling  line.  It  may 
fairly  be  doubted  whether  any  gen- 
eralization, or  hypothesis,  based  upon 
physical  data  is  absolutely  true,  in 
the  sense  that  a  mathematical  proposi- 
tion is  so;  but,  if  its  errors  can  be- 
come apparent  only  outside  the  limits 
of  practicable  observation,  it  may  be 
just  as  usefully  adopted  for  one  of  the 
symbols  of  that  algebra  by  which  we 
interpret  nature,  as  if  it  were  abso- 
lutely true. 

The  development  of  every  branch 
of  physical  knowledge  presents  three 
st.tges  which,  in  their  logical  relation, 
are  s-'ccessive.  The  first  is  the  de- 
termination of  the  sensible  character 
and  order  of  the  phenomena.  This 
is  Natural  History^  in  the  original 
sense  of  the  term,  and  here  nothing 
but  observation  and  experiment  avail 
us.  The  second  is  the  determination 
of  the  constant  relations  of  the  phe- 
nomena thus  defined,  and  their  ex- 
pression in  rules  or  laws.  The  third 
is  the  explication  of  these  particular 


laws  by  deduction  from  »lie  most  gen- 
eral laws  of  matter  and  motion.  The 
last  two  stages  constitute  Natural 
Philosophy  in  its  original  sense.  In 
this  region,  the  invention  of  verifiable 
hypotheses,  is  not  only  permissible, 
but  is  one  of  the  conditions  of  prog- 
ress. 

Historically,  no  branch  of  science 
has   followed   this  order  of  growth ; 
but,  from  the  dawn  of   exact  knowl- 
I  edge  to  the  present  day,  observation, 
I  experiment,    and     speculation     have 
I  gone   hand   in    hand;    and,  whenever 
I  science    has   halted  or  strayed   from 
I  the  right  path,  it  has  been,  either  be- 
[  cause  its  votaries  have  been   content 
I  with  mere  unverified  or  unverifiable 
speculation  (and  this  is  the  common- 
jest  case,  because  observation  and  ex- 
,  periment  are  hard   work,  while  spec- 
I  ulalion  is  amusing);  or   it   has  been, 
I  because   the  accunuilation  "of  details 
j  of  observation  has  for  a  time  excluded 
speculation. 

'J'he  progress  of  physical  science, 
since  the  revival  of  learning,  is  largely 
due  to  the  fact  that  men  have  giad- 
ually  learned    to    lay  aside   the   con- 
sideration of  unverifiable  hyjwtheses  ; 
to  guide  observation  and  experiment 
by  verifiable  hypotheses;  and  to  con- 
sider the   latter,  not  as   ideal  truths, 
the    real    entities    of    an    intelligible 
world  behind    phenomena,   but  as  a 
symbolical    langu.nge,  by   the   aid  of 
which  nature   can   be   interpreted   in 
terms  apprehensible  by  our  intellects. 
And  if   physical   science,  during  the 
last  fifty  years,  has   attained   dimen- 
sions beyond    all    former   piecedent, 
and    can     exhibit     acliievements    of 
,  greater  importance   than   any  former 
J  such  period  can   show,  it   is  because 
'  able  men,  animated  by  the  true  scien- 
I  tific   spirit,  carefully  trained   in    the 
I  method    of    science,   and    having    at 
'  their    disposal    immensely    improved 
\  appliances,  have  devoted  themselves 
I  to  the  enlargement  of  the  boundaries 
j  of  natural  knowledge  in  greater  num- 
I  ber  than  during   any  previous   half- 
century  of  the  world's  history. 

I  have  said  that  our  epoch  can  pro- 
duce achievements  in  physical  science 


1  •nrTBirBTT-T    T    r  r 


QMMiriU««MiBMiMBMa 


It; 


lO 


THE  ADVANCE  OF  SCIENCE 


of  greater  moment  than  any  other ;  all  such  masses  of  matter  possessed 
has  to  show,  advisedly ;  and  I  think  inertia  and  were  susceptible  of  ac- 
that  there  are  three  great  products  quiring  motion,  in  two  ways,  firstly 
of  our  time  Nv'-ich  justify  the  assertion. '  by  impact,  or  impulse  from  without; 
One  of  these  is  that  doctrine  concern-  and,  secondly,  by  the  operation  of 
ing  the  constitution  of  matter  which,  certain  hypothetical  causes  of  motion 
for  want  of  a  better  name,  I  will  call  termed  "forces,"  which  were  usually 
"  molecular ;  "  the  second  is  the  doc-  [  supposed  to  be  resident  in  the  parti- 
trine  of  conservation  of  energy;  the  i  cles  of  the  masses  themselves,  and  to 
third  is  the  doctrine  of  evolution. '  operate  at  a  distance,  in  such  a  way 
Each  of  these  was  foreshadowed,  as  to  tend  to  draw  any  two  such 
more  or  less  distinctly,  in  former  masses  together,  or  to  separate  them 
periods  of  the  history  of  science,  and,    more  widely. 

so  far  is  either  from  being  the  out- '.  VVitli  respect  to  the  ultimate  consti- 
come  of  purely  inductive  reasoning,  tution  of  tliese  masses,  the  snmt'  two 
that  It  would  be  hard  to  overrate  the  antagonistic  opinions  wiiich  had  ex- 
inHuence  of  metaphysical,  and  even  isted  since  the  time  of  Deniocritus 
of  theological,  considerations  upon  and  of  Aristotle  were  still  face  to 
the  development  of  ail  three.  The  face.  According  to  the  one,  matter 
peculiar  merit  of  our  epoch  is  that  it  was  discontinuous  and  consisted  of 
has  siiown  how  these  hypotheses  con  minute  indivisible  particles  or  atoms, 
nect  a  vast  number  of  seemingly  in-  separated  by  a  universal  vacuum  ;  ac- 
dependent  partial  generalizations ;  cording  to  the  other,  it  was  continu- 
that  it  has  given  them  that  precision  ous,  and  the  finest  distinguishable,  or 
of  expression  which  is  necessary  for  imaginable,  particles  were  scattered 
their  exact  verification ;  and  that  it  through  the  attenuated  general  sub- 
has  practically  proved  their  value  as  stance  of  the  plenum.  A  rough  nnal- 
guides  to  the  discovery  of  new  truth,  ogy  to  the  latter  case  would  be  afford- 
All  three  doctrines  are  intimately  ed  by  granules  of  ice  diffused  through 
connected,  and  each  is  applicable  to  water ;  to  the  former,  such  granules 
the  whole  physical  cosmos,  l^ut,  as  diffused  through  absolutely  empty 
might  have  been  expected   from  the   space. 

nature  of  the  case,  the  first  two  grew, !  In  the  latter  part  of  the  eighteenth 
mainly,  out  of  the  consideration  of  century,  the  chemists  had  arrived  at 
physico-chemical  phenomena;  while  ^  several  very  important  generalizations 
the  third,  in  great  measure,  owes  its  respecting  those  properties  of  matter 
rehabilitation,  if  not  its  origin,  to  the  ,  with  which  they  were  especially  con- 
study  of  biological  phenomena.  cerned.     However  plainly  ponderable 

matter  seemed  to  be   originated    and 

In  the  early  decades  of  this  cent- '  destroyed  in  their  operations,  they 
ury,  a  number  of  important  truths  ap-  proved  that,  as  mass  or  body,  it  re- 
plicable,  in  part,  to  matter  in  general,  mained  indestructible  and  ingenera- 
and,  in  part,  to  particular  forms  of  ble  ;  and  that,  so  far,  it  varied  only  in 
matter,  had  been  ascertained  by  the  its  perceptibility  by  our  senses.  The 
phvsicists  and  chemists.  '  course  of  investigation  further  proved 

The  laws  of  motion  of  visible  and ,  that  a  certain  number  of  the  chemi- 
tangible,  or  molar,  matter  had  been  |  cally  separable  kinds  of  matter  were  un- 
worked  out  to  a  great  degree  of  re-  alterable  by  any  known  means  (except 
finement  and  embodied  in  the  branches  in  so  far  as  they  might  be  made  to 
of  science  known  as  mechanics,  hy- ,  change  their  state  from  solid  to  fluid,  or 
drostatics,  and  pneumatics.  These  |  77?^  zwm),  unless  they  were  brought 
laws  had  been  shown  to  hold  go'^d,  so  j  into  contact  with  other  kinds  of  matter, 
far  as  they  could  be  checked  by  ob- j  and  that  the  properties  of  these  sev- 
servation  and  experiment,  throughout'  eral  kinds  of  matter  were  always  the 
the  universe,  on  the  assumption   that  same,    whatever    their    origin.       All 


IN  THE  LAST  HALF-CENTURY. 


II 


lerable 
;d    and 
IS,    they 
it   re- 
enera- 
lonly  in 
The 
I  proved 
chemi- 
lere  iin- 
|(except 
iiade  to 
jrtuid,  or 
)rought 
I  matter, 
Ise   sev- 
ivs  the 
All 


other  bodies  were  found  to  consist  of 
two  or  more  of  these,  which  thus  took 
ihe  place  of  the  four  "  elements  "  of 
the  ancient  philosophers.  Further,  it 
was  proved  that,  in  forming  chemical 
compounds,  bodies  always  unite  in  a 
definite  proportion  by  weight,  or  in 
simple  multiples  of  that  proportion, 
and  tliat,  if  any  one  body  were  taken 
as  a  standard,  every  other  could  have 
a  number  assigned  to  it,  as  its  pro- 
portional combining  weight.  It  was 
on  this  fouiKJation  of  fact  that  Dalton 
based  his  re-establishment  of  the  old 
atomic  hypothesis  on  a  new  empirical 
foundation.  It  is  obvious,  that  if  ele 
mentary  matter  consists  of  indestruc- 
lif)le  and  indivisible  particles,  each  of 
which  constantly  preserves  the  same 
weight  relatively  to  all  the  others, 
compounds  formed  by  the  aggrega- 
tion of  two,  three,  four,  or  more  such 
particles  must  exemplify  the  rule  of 
combination  in  definite  proportions 
deduced  from  observation. 

In  the  meanwhile,  the  gradual  recep- 
tion of  the  undulatory  theory  of  light 
necessitated  the  assumption  of  the  ex- 
istence of  an  "ether"  filling  all  space. 
But  whether  this  ether  was  to  be  re- 
garded as  a  strictly  material  and  con- 
tinuous substance  was  an  undecided 
point,  and  hence  the  revived  atomism 
escaped  strangling  in  its  birth.  For 
it  is  clear,  that  if  the  ether  is  aclmiiled 
to  be  a  continuous  material  substance, 
Democritic  atomism  is  at  an  end  and 
Cartesian  continuity  takes  its  place. 

The  real  value  of  the  new  atomic  hy- 
pothesis, however,  did  not  lie  in  the 
two  points  which  Democritus  and  his 
followers  would  have  considered  essen- 
tial— namely,  the  indivisibility  of  the 
"atoms"  and  the  presence  of  an  inter- 
atomic vacuum — but  in  the  assumption 
that,  to  the  extent  to  which  our  means 
of  analysis  lake  ns,  material  bodies 
consist  of  definite  minute  masses,  each 
of  which,  so  far  ;;s  physical  and  chem- 
ical processes  of  division  go,  may  be 
regarded  as  a  unit — having  a  practical 
pernianent  individuality.  Just  as  a 
man  is  the  unit  of  sociology,  without 
reference  to  the  actual  fact  of  his  di- 
visibility, so  such  a  minute  mass  is  the 


unit  of  physico-chemical  science — that 
smallest  material  panicle  which  under 
any  given  circumstances  acts  as  a 
whole.* 

The  doctrine  erf  specific  heat  orig- 
inated in  the  eighteenth  century.  It 
means  that  the  same  mass  of  a  body, 
under  the  same  circumstances,  alwavs 
requires  the  same  quantity  of  heat  to 
raise  it  to  a  given  temperature,  but  that 
equal  masses  of  different  bodies  re- 
quire different  quantities.  Ultimately, 
it  was  found  that  the  quanlitiesof  iieat 
required  to  raise  equal  masses  of  the 
more  perfect  gasses,  through  equal 
ranges  of  temperature,  were  inverse- 
ly proportional  to  their  combining 
weights.  Thus  a  definite  relation  was 
established  between  the  iivpothetical 
units  and  heat.  The  phenomena  of 
electrolytic  decomposition  showed  that 
there  was  alike  close  relation  between 
these  Units  and  electricity.  The  quan- 
titv  of  electricity  generated  by  the  com- 
bination of  any  two  units  is  sufficient  to 
separate  any  other  two  which  are  sus- 
ceptible of  such  decomposition.  The 
phenomena  of  isomorpliism  showed  a 
relation  between  the  units  and  crystal- 
line forms;  certain  units  are  thus  able 
to  replace  others  in  a  crystalline  body 
without  altering  its  form,  and  others 
are  not. 

Again,  the  laws  of  the  effect  of  press- 
ure and  heat  on  gaseous  bf)dies,  the 
fact  that  they  combine  in  definite  pro- 
portions by  volume,  and  that  such  pro- 
portion bears  a  simple  relation  to  tlieir 
combining  weights,  all  harmonized 
will)  the  Daltonian  hypothesis,  and  led 
to  the  bold  speculation  known  as  the 
law  of  Avogadio — that  all  gaseous  bod- 
ies, under  the  same  physical  condi- 
tions, contain  the  same  number  of 
units.  In  the  form  in  which  it  was 
first  enunciated,  this  hypothesis  was 
incorrect — perliajis  it  is  not  exactly 
true  in  any  form  ;  but  it  is  hardly  too 
much  to  say   that  chemistry  and   mo- 


j  *"  M(il<  rule  "would  l)c  the  inoio  anpropr'- 
I  ate  iKiini' liir  Mich  ;\  iiarticlc.  UntOrttipatelv, 
chemists  cinphiy  this  trim  in  a  spc-ial  sense, 
j  as  a  n.iim'  for  :)n  n'/tiretiation  of  tlicir  siiiil'i  st 
i  partich's.  for  whicli  ihcy  i':taii>  tiic  clusiL^ii.iliun 
■  ol  ".Uoins." 


13 


THE  ADVANCE  OF  SCIENCE 


lecular  physics  would  never  have  ad- 
vanced to  their  present  condition  un> 
less  it  had  been  assumed  to  be  true. 
Another  immense  service  rendered  by 
Dalton,  as  a  corollary  of  the  new  atom- 
ic doctrine,  was  the  creation  of  a  sys- 
tem of  symbolic  notation,  which  not 
only  made  the  nature  of  chemical  com- 

{)ouncls  and  processes  easily  intelligi- 
)le  and  easy  of  recollection,  but,  by 
its  very  form,  suggested  new  lines  of 
inquiry.  The  atomic  notation  was  as 
serviceable  to  chemistry  as  the  binom- 
ial nomenclature  and  the  classifrca- 
tory  schematism  of  Linna:us  were  to 
zoology  and  botany. 

Side  by  side  with  these  advances 
arose  Another,  which  also  h^s  a  close 
parallel   in  the  history  ot  biological 
science.     If  the  unit  ot  a  compound 
is  made  up  by  the  aggregation  of  ele- 
mentary units,  the  notion  that  these 
must  have  some   sort  of  definite  ar- 
rangement inevitably  suggests  itseli  ; 
and  such  phenomena  as  double  de- 
composition pointed  not  only  to  the 
existence  of  a  molecular  architecture, 
but  to  the  possibility  of  modifying  a 
molecular  fabric  without  destroying  it, 
by  taking  out  some  of  the  component 
units  and  replacing  them  by  others. 
The  class  of    neutral  saltS,  for  exam- 
ple, includes  a  great  number  of  bodies 
in  many  ways  similar,  in  which   the 
basic   molecules,  or   the  acid    mole- 
cules, may  be  replaced  by  other  basic 
and  other  acid  molecules  without  al- 
tering the  neutrality  of  the  salt ;  just 
as  a  cube  of  bricks  remains  a  cube, 
so  long  as  any  brick  that  is  taken  out 
is  replaced   by  another  of  the  same 
shape   and  dimensions,  whatever  its 
weight  or  other  properties  may  be. 
Facts  of  this  kind  gave  rise  to  the 
conception  of  "  types  "   of  molecular 
structure,  just  as   the  recognition  of 
the  unity  in  diversity  of  the  structure 
,of  the  species  of  plants  and  animals 
gave  rise  to  the  notion  of  biological 
i"  types."    The  notation  of  chemistry 
enabled  these  ideas  to  be  represented 
with  precision  ;  and  they  acquired  an 
immense   importance,  when   the   im- 
provement of   methods   of    analysis, 
which  took  place  about  the  beginning 


of  our  period,  enabled  the   composi- 
tion of  the  so-called  "  organic  "  bodies 
to  be  determined  with  rapidity  and 
precision.*      A    large  proportion  of 
these   compounds  contain   not   more 
than  three  or  four  elements,  of  which 
carbon  is  the  chief ;  but  their  num- 
ber is  very  great,  and  the  diversity  of 
their  physical  and  chemical   proper- 
ties is   astonishing.      The   ascertain- 
ment of  the  proportion  of  each  ele- 
ment in  these  compounds  affords  little 
or  no    help    toward    accounting  for 
their  diversities;  widely  different  bod- 
ies being  often  very  similar,  or  even 
identical,  in  that    respect.     And,  in 
the  last  case,  that  of  isomeric  com- 
pounds, the  appeal  to  dive;sity  of  ar- 
rangement   of   the   identical  compo- 
nent units  was  the  only  obvious  way 
out  of   the   difficulty.     Here,   again, 
hypothesis  proved   to    be    of    great 
value ;  not  only  was  the    search  for 
evidence   of    diversity  of    molecular 
structure  successful,  but  the  study  of 
the  process  of  taking  to  pieces  led  to 
the  discovery  of  the   way  to  put   to- 
gether ;  and    vast    numbers  of  com- 
pounds, some    of    them     previously 
known  only  as  products  of  the   living 
economy,  have  thus  been  artificially 
constructed.     Chemical  work,  at   the 
present  day,  is,  to  a  large  extent,  syn- 
thetic or  creative — that  is  to  say,  the 
chemist     determines,     theoretically, 
that  certain  non-existent  compounds 
ought  to  be  producible,  and  he  pro- 
ceeds to  produce  them. 

It  is  largely  because  the  chemical 
theory  and  practice  of  our  epoch 
have  passed  into  this  deductive  and 
synthetic  stage,  tl.at  they  are  entitled 
to  the  name  of  the  "  new  chemistry  " 
which  they  commonly  received.  But 
this  new  chemistry  has  grown  up  by 
the  help  of  hypotheses,  such  as  those 
of  Dalton  and  of  Avogadro,  and  that 
singular  conception  of  "  bonds  "  in- 
vented to  colligate  the  facts  of  "val- 
ency "   or   "  atomicity,"   the   first   of 


*  "  At  present  more  organic  analyses  are 
made  in  a  single  day  than  were  accomplished 
before  Liebig's  time  in  a  whole  year." — Hof- 
mann,  Faraday  Lecture,  p.  46. 


IN  THE  LAST  HALF-CENTURY. 


13 


nposi- 

)odies 

y  and 

ion  of 
more 

which 
num- 

sity  of 

)roper- 

ertauv 

;h  de- 
ls Uttle 

ng  for 

ntbod- 

r  even 

^nd,  in 

c  com- 

:  of  ar- 

conipo- 

)us  way 

again, 

great 

.rch  for 

olecular 

study  of 

i  led  to 
put   to- 

of  coni- 

eviously 

e   living 

tificially 
,  at  the 
nt,  syn- 
say,  the 
etically, 
ipounds 
he  pro- 
chemical 
epoch 
Itive  and 
entitled 
fmistry  " 
:d.     But 
in  up  by 
las  those 
land  that 
ids"  in- 
of  "  val- 
first   of 


[alyses  are 
jmplished 
•— Ho!- 


which  took  some  time  to  make  its 
way;  while  the  second  fell  into  obliv- 
ion,  for  many  years  after  it  was  pro- 
pounded, for  lack  of  empirical  justifi- 
cation. As  for  the  third,  it  may  be 
doubted  if  anyone  regards  it  as  more 
than  a  temporary  contrivance. 

But  some  of  these  hypotheses  have 
done  yet  further  service.  Combining 
them  with  the  mechanical  theory  of 
heat  and  the  doctrine  of  the  conser 
vation  of  energy,  which  are  also  pro- 
ducts of  our  time,  physicists  have  ar- 
rived at  an  entirely  new  conception 
of  the  nature  of  gaseous  bodies  and 
of  the  relation  of  the  physico-chemi- 
cal units  of  matter  to  the  different 
forms  of  energy.  The  conduct  of 
gases  under  varying  pressure  and 
temperature,  their  diffusibility,  their 
relation  to  radiant  heat  and  to  light, 
the  evolution  of  heat  when  bodies 
combine,  the  absorption  of  heat  when 
they  are  dissociated,  and  a  host  of 
other  molecular  phenomena,  have 
been  shown  to  be  deducible  from  the 
dynamical  and  statical  principles 
which  apply  to  molar  motion  and 
rest;  and  the  tendency  of  physico- 
chemical  science  is  clearly  toward 
the  reduction  of  the  problems  of  the 
world  of  the  infinitely  little,  as  it  al- 
ready has  reduced  those  of  the  infi- 
nitely great  world,  to  questions  of 
mechanics.* 

In  the  meanwhile,  the  primitive 
atomic  theory,  which  has  served  as 
the  scaffolding  for  the  edifice  of  mod- 
ern physics  and  chemistry,  has  been 
quietly  dismissed.  I  cannot  discover 
that  any  contemporary  physicist  or 
chemist  believes  in  the  real  indivisi- 
bility of  atoms,  or  in  an  interatomic 
matterless  vacuum.  "  Atoms  "  ap- 
pear to  be  used  as  mere  names  for 
physico-chemical  units  which  have 
not  yet  been  subdivided,  and  "  mole- 
cules "    for     physico-chemical    units 


•  In  the  preface  to  his  Af/canique  Chimi- 
que  M.  Berthelot  declares  his  object  to  be 
"  ramener  la  chimic  tout  entitre  .  .  .  . 
aux  memes  principes  mecaniques  qui  re- 
gissent  d^j^  les  diverses  branches  de  la  phy- 
sique." 


which  are  aggregates  of  the  former. 
And  these  individualized  particles  are 
supposed  to  move  in  r.ii  endless  ocean 
of  a  vastly  more  subtle  matter — tne 
ether.  If  this  ether  is  a  continuous 
substance,  therefore,  we  have  got  back 
from  the  hypothesis  of  Dalton  to  that 
of  Descartes.  But  there  is  much  rea- 
son to  believe  that  science  is  going 
to  make  a  still  further  journey,  and, 
in  form,  if  not  altogether  in  substance, 
to  return  to  the  point  of  view  of  Aris- 
totle. 

The  greater  number  of  -the  so- 
called  "  elementary  "  bodies,  now 
known,  had  been  discovered  before 
the  commencement  of  our  epoch , 
and  it  had  become  apparent  that  they 
were  by  no  means  equally  similar  or 
dissimilar,  but  that  some  of  them,  at 
any  rate,  constituted  groups,  the  sev- 
eral members  of  which  were  as  much 
like  one  another  as  they  were  unlike 
the  rest.  Chlorine,  iodine,  bromine, 
and  fluorine  thus  formed  a  very  dis- 
tinct group;  sulphur  and  selenium 
another;  boron  and  silicon  another; 
potassium,  sodium,  and  lithium  an- 
other ;  and  so  on.  In  some  cases, 
the  atomic  weights  of  such  allied 
bodies  were  nearly  the  same  or  could 
be  arranged  in  series,  with  like  dif- 
ferenceJ  between  the  several  terms. 
In  fact,  the  elements  afforded  indica- 
tions that  they  were  susceptible  of  a 
classification  in  natural  groups,  such 
as  those  into  which  animals  and 
plants  fall. 

Recently  this  subject  has  been 
taken  up  afresh,  with  a  result  which 
may  be  stated  roughly  in  the  follow- 
ing terms:  If  the  sixty-five  or  sixty- 
eight  recognized  "elements"  are 
arranged  in  the  order  of  their  atomic 
weights — from  hydrogen,  the  lightest, 
as  unity,  to  uranium,  the  heaviest,  as 
240 — the  series  does  not  exhibit  one 
continuous  progressive  modification 
in  the  physical  and  chemical  charac- 
ters of  its  several  terms,  but  breaks 
up  into  a  number  of  sections,  in  each 
of  which  the  several  terms  present 
analogies  with  the  corresponding 
terms  of  the  other  series. 


mmm» 


H 

Thus 
run 


THE  ADVANCE  OF  SCIENCE 


the  whole  series  does  not 


a,  6,  c,  J,  f,/,  g,  //,  /,  k,  etc., 


but 


a,  d,  r,  d,  a,  b,  c,  d,  «,  Pt  7,  •J.  etc. ; 

so  that  it  is  said  to  express  ^periodic 
laiv  of  recurrent  similarities.  Or  the 
relation  may  be  expressed  in  another 
way.  In  each  section  of  the  series, 
the  atomic  weight  is  greater  than  in 
the  preceding  section,  so  that  if  w  is 
the  atomic  weight  of  any  element  in 
the  first  segment,  w-\-x  will  represent 
the  atomic  weight  of  any  element  in 
the  next,  and  w-\-x-\-y  the  atomic 
weight  of  any  element  in  the  next, 
and  so  on.  Therefore  the  sections 
may  be  represented  as  parallel  series, 
the  corresponding  terms  of  which 
have  analogous  properties  ,  each  suc- 
cessive series  starling  with  a  body  the 
atomic  weight  of  which  is  greater 
than  th^t  of  any  in  the  preceding 
series,  in  the  following  fashion : 


d 
c 
h 
a 

w 


D 
C 

B 
A 


7 

P 
a 


ttf+x  w+x+y 


This  is  a  conception  with  which 
biologists  are  very  familiar,  animal 
and  plant  groups  constantly  appearing 
as  series  of  parallel  modifications  of 
similar  and  yet  different  primary 
forms.  In  the  living  world,  facts  of 
this  kind  are  now  understood  to  mean 
evolution  from  a  common  prototype. 
It  is  difficult  to  imagine  that  in  the 
not-living  world  they  are  devoid  of 
significance.  Is  it  not  possible,  nay 
probable,  that  they  may  mean  the 
evolution  of  our  "elements'"  from  a 
primary  undifferentiated  form  of 
matter  ?  Fifty  years  ago,  such  a  sug- 
gestion would  have  been  scouted  as 
a  revival  of  the  dreams  of  the  alche- 
mists.   At  present,  it  may  be  said  to 


be  the  burning  question  of  physico- 
chemical  science. 

In  fact,  the  so-called  "  vortex-ring  " 
hypothesis  is  a  very  serious  and  re- 
markable attempt  to  deal  with  mate- 
rial units  from  a  point  of  view  which 
is  consistent  with  the  doctrine  of  evo- 
lution. It  supposes  the  ether  to  be 
a  uniform  substance,  and  that  the 
"  elementary "  uniis  are,  broadly 
speaking,  permanent  whirlpools,  or 
vortices,  of  this  ether,  the  properties 
of  which  depend  on  their  actual  and 
potential  modes  of  motion.  It  is 
curious  and  highly  interesting  to  re- 
mark that  this  hypothesis  reminds  us 
not  only  of  the  speculations  of  Des- 
cartes, but  of  those  of  Aristotle. 
The  resemblance  of  the  "  vortex- 
rings  "  to  the  "  tourbillons  "  of  Des- 
cartes is  little  more  than  nominal ; 
but  the  correspondence  between  the 
modern  and  the  ancient  notion  of  a 
distinction  between  primary  and  de- 
rivative matter  is,  to  a  certain  extent, 
real.  For  this  ethereal  "  Urstoff  "  of 
the  modern  corresponds  very  closely 
with  the  niMr?}v/.i/  of  Aristotle,  the 
materia  prima  of  his  mediaeval  follow- 
ers ;  wliile  matter,  differentiated  into 
our  elements,  is  the  equivalent  of  the 
first  stage  of  progress  towards  the 
tax^'^n  i>'/,  or  finished  matter,  of  the 
ancient  philosophy. 

If  the  material  units  of  the  existing 
order  of  nature  are  specialized  por- 
tions of  a  relatively  homogeneous  ma- 
teriaprima — which  were  originated  un- 
der conditions  that  have  long  ceased 
to  exist  and  which  remain  unchanged 
and  unchangeable  under  all  conditions, 
whether  natural  or  artificial,  hitherto 
known  to  us — it  follows  that  the  spec- 
ulation that  they  may  be  indefinitely 
altered,  or  that  new  units  may  be  gen- 
erated under  conditions  yet  to  be  dis- 
covered, is  perfectly  legitimate.  The- 
oretic'dly,  at  any  rate,  the  transmuta- 
bility  of  the  elements  is  a  verifiable 
scientific  hypothesis  ;  and  such  inquir- 
ies as  those  which  have  been  set  afoot, 
into  the  possible  dissociative  action  of 
the  great  heat  of  the  sun  upon  our  ele- 
ments, are  not  only  legitimate,  but  are 
likely  to  yield  results  which  whether  af- 


IN  THE  LAST  HALF-CENTURY. 


15 


jxisting 
.'d  por- 
)us  ma- 
itedun- 

ceased 
hanged 
][litions, 

lilherto 


firmative  or  negative  will  be  of  great 
importance.  The  idea  that  atoms 
are  absolutely  ingenerable  and  immu- 
table "manufactured  articles"  stands 
on  the  same  sort  of  foundation  as  the 
idea  that  biological  species  are 
"  manufactured  articles  "  stood  thirty 
years  ago  ;  and  the  supposed  constan- 
cy of  the  elementary  atoms,  durini; 
the  enormous  lapse  of  time  measured 
by  the  existence  of  our  universe,  is  of 
no  more  weight  against  the  possibility 
of  change  in  them,  in  the  infinity  of 
antecedent  time,  than  the  constancy 
of  species  in  Kgypt,  since  the  days  of 
Rameses  or  Cheops,  is  evidence  of 
their  immutability  during  all  past 
epochs  of  the  earth's  history.  It 
seems  safe  to  prophesy  that  the  hy- 
pothesis of  the  evolution  of  the  ele- 
ments from  a  primitive  matter  will,  in 
future,  play  no  less  a  part  in  the  his- 
tory of  science  than  the  atomic  hy- 
pothesis, v.iuch,  to  bei;in  with,  had  no 
greater,  if  so  great,  an  empirical  fonn 
dation. 

It  may  perhaps  occur  to  the  reader 
that  the  boasted  progress  of  physical 
science  does  not  come  to  much,  if 
our  present  conceptions  of  the  funda- 
mental nature  of  matter  are  expressi- 
ble in  terms  employed,  more  than  two 
thousand  years  ago,  by  the  old  "  mas- 
ter of  those  that  know."  Such  a 
criticism,  however,  would  involve  for- 
getfulness  of  the  fact,  that  the  conno- 
tation of  these  terms,  in  the  mind  of 
the  modern,  is  almost  infinitelv  differ- 
ent  from  that  which  they  possessed  in 
the  mind  of  the  ancient,  philosopher. 
In  antiquity,  they  meant  little  more 
than  vague  speculation ;  at  the  pres- 
ent day,  they  indicate  definite  physi- 
cal conceptions,  susceptible  of  mathe- 
matical treatment,  and  giving  rise  to 
innumerable  deductions,  the  value  of 
which  can  be  experimentally  tested. 
The  old  notions  produced  little  more 
than  floods  of  dialectics  ;  the  new  are 
powerful  aids  toward  the  increase  of 
solid  knowledge. 

Everyday  observation  shows  that, 
of  the  bodies  which  compose  the  ma- 
terial world,  some  are  in  motion  and 
some  are,  or  appear  to  be,  at  rest. 


C  the  bodies  in  motion,  some,  like 
the  sun  and  stars,  exhibit  a  constant 
movement,  regular  in  amount  and 
direction,  for  which  no  external  cause 
appears.  Others,  as  stones  and 
smoke,  seem  also  to  move  of  them- 
selves when  external  impediments  are 
taken  away.  But  these  appear  to 
tend  to  move  in  opposite  directions  : 
the  bodies  we  call  heavy,  such  as 
stones,  downwards,  and  the  bodies  we 
call  light,  at  le.ist  such  as  smoke  and 
steam,  upwards.  And,  as  we  further 
notice  that  the  earth,  below  our  feet, 
is  made  up  of  heavy  matter,  while  the 
air,  above  our  heads,  is  extremely 
light  matter,  it  is  easy  to  regard  this 
fact  as  evidence  that  the  lower  rej^ion 
is  the  place  to  which  heavy  things 
tend — their  ])roper  place,  in  short — 
while  the  upper  region  is  the  proper 
place  of  light  things  ;  and  to  general- 
ize the  facts  observed  by  saying  that 
bodies,  which  are  free  to  move,  tend 
toward  their  proper  places.  Ail  these 
seem  to  be  natural  moirrtns,  depend- 
ent on  the  inherent  faculties,  or  ten- 
dencies, of  bodies  themselves.  But 
there  are  other  motions  which  are 
artificial  or  violent,  as  when  a  stone 
is  thrown  from  the  hand,  or  is  knocked 
by  another  stone  in  motion.  In  such 
cases  as  these,  for  example,  when  a 
stone  is  cast  from  the  hand,  the  dis- 
tance traveled  by  the  stone  appears 
to  depend  partly  on  its  weight  and 
partly  upon  the  exertion  of  the  throw- 
er. So  that,  the  weight  of  the  stone 
remaining  the  same,  it  looks  as  if  the 
motive  power  communicated  to  it 
were  measured  by  the  distance  to 
which  the  stone  travels — as  if,  in 
other  words,  the  power  needed  to 
send  it  a  hundred  yards  was  twice  as 
great  as  that  needed  to  send  it  fifty 
yards.  These,  apparently  obvious, 
conclusions  from  the  everyday  ap- 
pearances of  rest  and  motion  fairly 
represent  the  state  of  opinion  upon 
the  subject  which  prevailed  among 
the  ancient  Greeks,  and  remained 
dominant  until  the  age  of  Galileo. 
The  publication  of  the  "  Principia  "  of 
Newton,  in  1686-7,  marks  the  epoch 
at  which  the  progress  of  mechanical 


1^ 


THE  ADVANCE  OF  SCIENCE 


physics  had  effected  a  complete  rev- 
olution of  thought  on  these  subjects. 
By  this  time,  it  had  been  made  clear 
that  the  old  generalizations  were 
either  incomplete  or  totally  errone- 
ous ;  that  a  body,  once  set  in  motion, 
will  continue  to  move  in  a  straight 
line  for  any  conceivable  time  or  dis- 
tance, unless  it  is  interfered  with ; 
that  any  change  of  motion  is  propor- 
tional to  the  "  force  "  which  causes  it, 
and  takes  place  in  the  direction  in 
which  that  "  force  "  is  exerted ;  and 
that,  when  a  body  in  motion  acts  as 
a  cause  of  motion  on  another,  the 
latter  gains  as  much  as  the  former 
loses,  and  Tice  versa.  It  is  to  be 
noted,  however,  that  while,  in  con- 
tradistinction to  the  ancient  idea  of 
the  inherent  tendency  to  motion  of 
bodies,  the  absence  of  any  such  spon- 
taneous power  of  motion  was  accepted 
as  a  physical  axiom  by  the  moderns, 
the  old  conception  virtually  main- 
tained itselt  in  a  new  shape.  For,  in 
spite  of  Newton's  well-known  warn- 
ing against  the  "absurdity"  of  sup- 
posing that  one  body  can  act  on 
another  at  a  distance  through  a  va- 
cuum, the  ultimate  particles  of  matter 
were  generally  assumed  to  be  the 
seats  of  pe  ennial  causes  of  motion 
termed  "  attractive  and.  repulsive 
forces,"  in  virtue  of  which,  any  two 
such  particles,  without  any  external 
impression  of  motion,  or  intermediate 
material  agent,  were  supposed  to  tend 
to  approach  or  remove  from  one  an- 
other ;  and  this  view  of  the  duality  of 
the  causes  of  motion  is  very  widely 
held  at  the  present  day. 

Another  important  result  of  inves- 
tigation, attained  in  the  seventeenth 
century,  was  the  proof  and  quantita- 
tive estimat'on  of  physical  inertia. 
In  the  old  philosophy,  a  curious  con- 
junction of  ethical  and  physical  prej- 
udices had  led  to  the  notion  that 
there  was  something  ethically  bad 
and  physically  obstructive  about 
matter.  Aristotle  attributes  all  ir- 
regularities and  apparent  dysteleolo- 
gies  in  nature  to  the  disobedience, 
or  sluggish  yielding,  of  matter  to  the 
shaping    and    guiding    influence    of 


those  reasons  and  causes  which  were 
hypostatized  in  his  ideal  "forms." 
In  modern  science,  the  conception  of 
the  inertia,  or  resistance  to  change, 
of  matter  is  complex.  In  part,  it 
contains  a  corollary  from  the  law  of 
causation  :  A  body  cannot  change 
its  state  in  respect  of  rest  or  motion 
without  a  sufficient  cause.  But,  in 
part,  it  contains  generalizations  from 
experience.  One  of  these  is  that 
there  is  no  such  sufficient  cause  resi- 
dent in  any  body,  and  that  therefore 
it  will  rest,  or  continue  in  motion,  so 
long  as  no  external  cause  of  change 
acts  upon  it.  The  other  is  that  the 
effect  which  the  impact  of  a  body  in 
motion  produces  upon  the  body  on 
which  it  impinges  depends,  other 
things  being  alike,  on  the  relation  of 
a  certain  quality  of  each  which  is 
called  "  mass."  Given  a  cause  of 
motion  of  a  certain  value,  the  amount 
of  motion,  measured  by  distance  trav- 
eled in  a  certain  time,  which  it  will 
produce  in  a  given  quantity  of  matter, 
say  a  cubic  inch,  is  not  always  the 
same,  but  depends  on  what  that  mat- 
ter is — a  cubic  inch  of  iron  will  go 
faster  than  a  cubic  inch  of  gold. 
Hence,  it  appears,  that  since  equal 
amounts  of  motion  have,  ex  hypothcsi, 
been  produced,  the  amount  of  motion 
in  a  body  does  not  depend  on  its 
speed  alone,  but  on  some  property  of 
the  body.  To  this  the  name  of 
"  mass  "  has  been  given.  And  since 
it  seems  reasonable  to  suppose  that  a 
large  quantity  of  matter,  moving 
slowly,  possesses  as  much  motion  as 
a  small  quantity  moving  faster, 
"  mass "  has  been  held  to  express 
"quantity  of  matter."  It  is  further 
demonstrable  that,  at  any  given  time 
and  place,  the  relative  mass  of  any 
two  bodies  is  expressed  by  the  ratio 
of  their  weights. 

When  all  these  great  truths  respect- 
ing molar  motion,  or  the  movements 
of  visible  and  tangible  masses,  had 
been  shown  to  hold  good  not  only  of 
terrestrial  bodies,  but  of  all  those 
which  constitute  the  visible  universe, 
and  the  movements  of  the  macrocosm 
had  thus  been  expressed  by  a  general 


ilil 


IN  THE   LAST  IIAI.F-CEN'TURY. 


»7 


1  were 

arms." 

ion  of 

hange, 

lart,   it 

law  of 

change 

motion 

But,  in 

s  from 

is    that 

se  resi- 

lerefore 

tion,  so 

change 

hat  the 

body  in 

)ody  on 

;,    other 

ation  of 

vhich   is 

;ause   of 

I  amount 

nee  trav- 

h  it  will 

if  matter, 

A'ays  the 

hat  mat- 

}  will  go 

of   gold. 

ce  equal 

hypothcsiy 
'  motion 
on   its 
iperty  of 
lame    of 
nd  since 
se  that  a 
moving 
otion  as 
faster, 
express 
further 
ven  time 
of  any 
the  ratio 

respect- 
jvements 
^ses,  had 
|)t  only  of 
ill  those 
luniverse, 

icrocosm 
general 


n 


mechanical  theory,  there  remained  a 
vast  number  of  phenomena,  such  as 
those  of  light,  heat,  electricity,  mag- 
netism, and  those  of  the  physical  and 
chemical  changes,  which  clo  not  in- 
volve molar  moiion.  Newton's  cor- 
puscular theory  of  light  was  an  at- 
tempt to  deal  with  one  great  series  of 
these  phenomena  on  mechanical  prin- 
ciples, and  it  maintained  its  ground  un- 
til, at  the  beginning  of  the  nineteenth 
century,  the  undulatory  theory  proved 
itself  to  be  a  much  better  working 
hypothesis.  Heat,  up  to  that  time, 
and  indeed  much  later,  was  regarded 
as  an  imponderable  substance,  caloric ; 
as  a  thing  which  was  absorbed  by 
bodies  when  they  were  warmed,  and 
was  given  out  as  they  cooled  ;  and 
which,  moreover,  was  capable  of  en- 
tering into  a  sort  of  chemical  com- 
bination with  them,  and  so  becoming 
latent.  Rumford  and  Davy  had 
given  a  great  blow  to  this  view  of  heat 
by  proving  that  the  quantity  of  heat 
which  two  portions  of  the  same  body 
could  be  made  to  give  out,  by  rubbing 
them  together,  was  practically  illimi- 
table. This  result  brought  philoso- 
phers face  to  face  with  the  contradic- 
tion of  supposing  that  a  finite  body 
could  contain  an  infinite  quantity  of 
another  body;  but  it  was  not  until 
1843,  that  clear  and  unquestionable 
experimental  proof  was  given  of  the 
fact  that  there  is  a  definite  relation 
between  mechanical  work  and  heat ; 
that  so  much  work  always  gives  rise, 
under  the  same  conditions,  to  so  much 
heat,  and  so  much  heat  to  so  much 
mechanical  work.  Thus  originated 
the  mechanical  theory  of  heat,  which 
became  the  starting-point  of  the  mod- 
ern doctrine  of  the  conservation  of 
energy.  Molar  motion  had  appeared 
to  be  destroyed  by  friction.  It  was 
proved  that  no  destruction  took  place, 
but  that  an  exact  equivalent  of  the 
energy  of  the  lost  molar  motion  ap- 
pears as  that  of  the  molecular  motion, 
or  motion  of  the  smallest  particles  of 
a  bod}',  which  constitutes  heat.  The 
loss  of  the  masses  is  the  gain  of  their 
particles. 
Before  1843,  however,  the  doctrine 


of  the  conservation  of  energy  had 
been  approached.  Bacon's  chief  con- 
tribution to  positive  science  is  the 
happy  guess  (for  the  context  shows 
that  it  was  little  more)  that  hent 
may  be  a  mode  of  motion  ;  Descartes 
affirmed  the  quantity  of  motion  in 
the  world  to  be  constant ;  Newton 
nearly  gave  expression  to  the  com- 
plete theorem  ;  while  Rumford's  and 
Davy's  experiments  suggested,  though 
they  did  not  prove,  the  equivalency 
of  mechanical  and  thermal  energy. 
Again,  the  discovery  of  voltaic  elec- 
tricity, and  the  marvelous  develop- 
ment of  knowledge,  in  that  field, 
effected  by  such  men  as  Davy,  Fara 
day.  Oersted,  Ampere,  and  Melloni, 
had  brought  to  light  a  number  of  facts 
which  tended  to  show  that  the  so- 
called  •'  forces  "  at  work  in  light,  heat, 
electricity,  and  magnetism,  in  chemi- 
cal and  in  mechanical  operations, 
were  intimately,  and,  in  various  cases, 
quantitatively  related.  It  was  demon- 
strated that  any  one  could  be  ob- 
tained at  the  expense  of  any  other ; 
and  apparatus  was  devised  which  ex- 
hil?ited  the  evolution  of  all  these  kinds 
of  action  from  one  source  of  energy. 
Hence  the  idea  of  the  "  correlation 
of  forces "  which  was  the  immediate 
forerunner  of  the  doctrine  of  the  con- 
servation of  energy.  ^^ 
It  is  a  remarkable  evidence  of  the 
greatness  of  the  progress  in  this  direc- 
tion which  has  been  effected  in  our 
time,  that  even  the  second  edition  of 
the  "  History  of  the  Inductive  Scien- 
ces," which  was  published  in  1846, 
contains  no  allusion  either  to  the  gen- 
eral view  of  the  "Correlation  of 
Forces "  published  in  England  in 
1842,  or  to  the  publication  in  1843  of 
the  first  of  the  series  of  experiments 
by  which  the  mechanical  equivalent 
of  heat   was    correctly   ascertained.* 


•  This  is  the  more  curious,  as  Amptre'H- 
hypothcsis    that    vibrations    of    molecules, 
causing   and  caused  by  vibrations    of    the 
ether,  constitute  heat,  is  discussed.     See  vol. 
ii.  p.  587,  2nd  ed.     In  the  Philosophy  of  the 
Inductwe  Sciences,    2nd  ed..    1847,    p.    239,. 
Whewell  remarks,  h  propos  of  ISacon's  defini-- 
tion  of  beat,  "  that  it  ia  an  expansive,  re- 


i8 


Till-:  ADVANCE  OF  SCIENCE 


Such  a  failure  on  the  part  of  a  con- 
Icmpfirary,  of  j^roat  ac(|uiremems  and 
rcmaikable  iiucllccuial  powers,  to 
read  ihc  signs  of  the  times,  is  a  li'sson 
and  a  wainini;  worthy  of  being  deeply 
Ijondered  by  anyone  who  attempts  to 
pro{;noslicaie  the  course  of  scientific 
progress. 

1  have  pointed  out  that  the  growth 
of  clear  and  delinite  views  respecting 
the  constitution  of  matter  has  led  to 
the  conclusion  that,  so  far  as  natural 
agencies  are  concerned,  it  is  ingener- 
ai)le  and  indestructible.     In  so  far  as 
matter  may  be  conceived  to  exist  in  a 
purely  passive  state,  it  is,  imaguiably, 
older   than    motion.     But,  as  it  must 
be  assumed  to  be  .susceptible  of  mo- 
tion, a  particle  of   bare  matter  at   rest 
must  be  endowed  wuh  the  potentiality 
of  motion.     Such  a  panicle,  however, 
by  the  supposition,  can   iiave  no  en- 
tirgy,    for   there    is    no   cause  why  it 
should  move.      Suppose   now  that   it 
receives  an  impulse,  it   will  begin   to 
move  with   a  velocity   inversely    pro- 
portional   to   Its    mass,    on    the    one 
hand,  and  directly  jiroportional  to  the 
strength  of  the  impulse,  on  the  other, 
and  will   j^ossess  kinetic  energy,  in  vir- 
tue of  which  it  will  not  only  continue 
to  move  forever  if  unimpeded,  but  if 
it  impinges  on  another  such  particle, 
it  will  impart  more  or  less  of  its  mo- 
tion to  the  latter.     Let  it  be  conceived 
that  the  particle  acquires  a  tendency 
to  move,  and  that  nevertheless  it  does 
not  move.     It  is  then  in  a  condition 
totally  different  from  that  in  which  it 
was  at  first.     A  cause  competent  to 
produce  motion  is  operating  upon  it, 
but,  for  some  reason  or  other,  is  un 
able  to  give  rise  to  motion.     If  the 


strained  motion,  modified  in  certain  w.ays, 
and  exerted  in  the  smaller  particles  of  the 
body;"  that  "although  the  exact  nature  of 
heat  is  still  an  obscure  and  controverted 
matter,  the  science  of  heat  now  consists  of 
many  imjiortant  truths  ;  and  that  to  none  of 
these  truths  is  there  any  approximation  in 
l?acon's  essay."  In  point  of  fact,  Hacon's 
statemrnt,  however  much  open  to  criticism, 
does  contain  a  distinct  approximation  to  the 
most  important  of  all  the  truths  respecting 
heat  which  had  been  discovered  when 
Whewell  wrote. 


obstacle  is  removed,  the  energy  which 
was  there,  but  could  not  manifest  it- 
self, at  once  gives  rise  to  motion. 
While  the  restraint  lasts,  the  energy 
of  the  particle  is  merely  potential  ; 
and  the  case  supjiosed  illustrates  wiiai 
is  meant  by  potential  energy.  In  this 
contrast  of  the  potential  with  the  actual, 
modern  physics  is  turning  to  account 
the  most  familiar  of  Aristotelian  dis- 
tinctions—  that  between    <''k'/"V   and 

That  kinetic  energy  appears  to  be 
im|)arted  by  impact  is  a  fact  of  daily 
and  hourly  experience  :  we  see  bodies 
set  in  motion   by  bodies,   already  in 
motion,    which    seem     to    come     in 
contact   with    them.       It   is   a    truth 
which   could    have    been    learned    by 
nothing    but   experience,   and    which 
cannot   be    explained,    but    must   be 
taken  as  an  ultimate  fact  about  which, 
explicable  or  inexplicable,  there  can 
be  no  doubt.     Strictly  speaking,   we 
have  no  direct  apprehension  of  any 
other  cause  of   motion.     But  experi- 
ence furnishes  innumerable  examples 
of  the  production  of  kinetic  energy  in 
a  body  previously  at   rest,  when  no 
impact  is  discernible  as  the  cause  of 
that  energy.     In  all   such  cases,  the 
presence  of  a  second  body  is  a  neces- 
sary condition ;    and    the   amount   of 
kinetic  energy,  which  its  presence  en- 
ables  the   first  to  gain,  is  strictly  de- 
pendent on   the  relative  positions  of 
the  two.     Hence  the  phrase  etiergy  of 
position,  which  is  frequently  used  as 
equivalent  to  potential  energy.     If   a 
stone  is  picked  up  and  held,   say,  six 
feet  above  the  ground,  it  hti'-,  potential 
energy,  because,  if  let  go,  it  will  imme- 
diately  begin    to   move    toward    the 
earth  ;  and  this  energy  may  be  said  to 
be  energy  of  position,   because   it   de- 
pends upon  the  relative   position   of 
the  earth  and  the  stone.     The  stone 
solicited   to  move   but  cannot,  so 


IS 

long  as  the  muscular  strength  of  the 
holder  prevents  the  solicitation  from 
taking  effect.  The  stone,  therefore, 
has  potential  energy,  which  becomes 
kinetic  if  it  is  let  go,  and  the  amount 
of  that  kinetic  energy  which  will  be 
develooed  before  it  strikes  the  earth 


IN  THE  LAST  HALF-CKNTURY. 


19 


lot,  so 
hi  the 

from 
efore, 
tomes 

(lount 
till  be 
[earth 


depends  on  its  position — on  the  fact '  right-hand  half-swing.  It  is  said  that 
that  it  is,  say,  six  feel  off  the  earth, ,  the  "attractive  forces"  of  tlie  bob 
neiiix.T  more  nor  less.  Moreover,  it  for  the  earth,  and  of  the  earth  for  the 
can  be  proved  that  the  raiser  of  liie  bol),  set  the  former  in  motion ;  and 
stone  had  to  exert  as  much  energy  in  j  as  tliese  "  forces  "  are  continually  in 
order  to  place  it  in  its  position,  as  it  operation,  they  confer  an  accelerated 
will  (Lvclop  in  falling.  Hence  the  velocity  on  the  bob;  until,  when  it 
energy  which  was  exerted,  and  reaches  the  center  of  its  swing,  it  is. 
apparently  exhausted,  in  raising  ,  so  to  speak,  fully  charged  with  kinetic 
the  slouL',  is_  pottMUially  in  the  stone, ;  energy.  If,  at  this  moment,  the 
in  its  laisod  position,  and  will  m an i-  whole  material  universe,  except  the 
fest  itself  when  the  stone  is  set  free,  bob,  were  abolished,  it  would  move 
Thus  the  energy,  wiilulrawn  from  the  1  forever  in  the  direction  of  a  tangent 
general  stf)ck  to  raise  the  stone,  isre-jto  the  middle  of  the  arc  described, 
turned  when  it  falls,  and  there  is  no  1  As  a  matter  of  fact,  it  is  comjielled  to 
changL'  in  the  total  amount.  Energy,  I  travel  through  its  left-hand  half-swing, 
as  a  whoK',  is  conserved.  !  and     thus   virtually    to    go    up    hill. 

Taking  this  as  a  very  broad  and  Consequently,  the  "  attractive  forces  " 
general  stalenieiu  of  the  essential  of  the  bob  and  the  earth  are  now 
facts  of  tiie  case,  the  raising  of  the  acting  against  it,  and  constitute  a 
stone  is  inieliigible  enough,  as  a  case  I  resistance  which  the  charge  of  kinetic 
of  the  comnnniicalion  of  motion  from  energy  has  to  overcome.  IJut.  as  this 
one  body  to  another.  But  the  poten-  charge  represents  the  operation  of 
tial  energy  of  the  raised  stone  is  not ,  the  attractive  forces  during  the  pns- 
so  easily  intelligible.  To  all  appear-  sage  of  the  bob  through  the  right- 
ance,  there  is  nt)thing  either  pushing;  hand  half-swing  down  to  the  center  of 
or  pulling  it  toward  the  earth,  or  the  arc,  so  it  must  needs  be  used  up 
the  earth  toward  it;  and  yet  it  is |by  the  passage  of  the  bob  upwards 
quite  certain  that  the  stone  tends  to  from  the  center  of  the  arc  to  the  sum- 
move  toward  the  earth  and  the  earth  '  niit  of  the  left-hand  half-swing, 
toward  the  stone,  in  the  way  detined ;  Hence,  at  this  point,  the  bob  comes 
by  the  law  of  gravitation.  to  a  momentary  rest.     The  last  frac- 

In  the  currently  accepted  language  tion  of  kinetic  energy  is  just  neutral- 
of  science,  the  cause  of  motion,  in  all  '■  ized  by  the  action  of  the  attractive 
such  cases  as  this,  when  bodies  tend  forces,  and  the  bob  has  only  pottMitial 
to  move  toward  or  away  from  one  or ,  energv  equal  to  that  with  which  it 
another,  without  any  discernible  im- ,  started.  So  that  the  sum  of  the  phe- 
pact  of  other  bodies,  is  termed  a  i  nomena  may  be  stated  thus:  At  the 
"  force,"  which  is  called  "  attractive  "  \  summit  of  either  half  arc  of  its  swing, 
in  the  one  case,  and  "  repulsive  "  in  '  the  bob  has  a  certain  amount  of  po- 
the  other.  And  such  attractive  or  ,  tential  energy  ;  as  it  descends  it  grad- 
repvdsive  forces  are  often  spoken  of ;  ually  exchanges  this  for  kinetic  en- 
as  if  they  were  real  things,  capable  of.ergv,  until  at  the  center  it  possesses 
exerting  a  pull,  or  a  push,  upon  the  |  an  equivalent  amount  of  kinetic  en- 
particles  of  matter  concerned.  Thus  ergv ;  from  this  point  onwards,  it 
the  potential  energy  of  the  stone  is  gradually  loses  kinetic  energy  as  it 
commonly  said  to  be  due  to  the  ascends,  until,  at  the  summit  of  the 
"force"  of  gravity  which  is  contin- 1  other  half-arc,  it  has  acquired  an  ex- 
ually  operating  upon  it.  aclly  similar  amount  of  potential  en- 

Another  illustration  may  make  the  ergy  Thus,  on  the  whole  transaction, 
casa  plainer.  The  bob  of  a  pendu- ,  nothing  is  either  lost  or  gained ;  the 
lum  swings  first  to  one  side  and  then  j  quantity  of  energy  is  always  the  same, 
to  the  other  of  the  center  of  the  arc  1  but  it  passes  from  one  form  into  the 
which  It  describes.  Suppose  it  to ;  other, 
have  just  reached  the  summit  of  its  I     To  all  appearance,  the  phenomena 


■•^ 


WW 


20 


THE  ADVANCE  OF  SCIENCE 


exhibited  by  the  pendulum  are  not  to 
be  accounted  for  by  impaci ;  in  fact, 
it  is  usually  assumed  that  correspond- 
'ing  phenomena  would  take  place  if 
the  earth  and  the  pendulum  were  sit- 
uated in  an  absolute  vacuum,  and  at 
any  conceivable  distance  from  one 
another.  If  this  be  so,  it  follows  that 
there  must  be  two  totally  different 
kmds  of  causes  of  motion  :  the  one 
impact — a  vera  causa,  of  which,  to  all 
appearance,  we  have  constant  expe- 
rience ;  the  other,  attractive  or  repul- 
sive "force" — a  metaphysical  entity 
which  is  physically  inconceivable. 
Newton  expressly  repudiated  the  no- 
tion of  the  existence  of  attractive 
forces  in  the  sense  in  which  that  term 
is  ordinarily  understood  \  and  he  re- 
fused to  put  forward  any  hypothesis 
as  to  the  physical  cause  of  the  so- 
called  "  attraction  of  gravitation." 
As  a  general  rule,  his  successors  have 
been  content  to  accept  the  doctrine 
of  attractive  and  repulsive  forces, 
without  troubling  themselves  about 
the  philosophical  difficulties  which  it 
involves.  But  this  has  not  always 
been  the  case ;  and  the  attempt  of  Le 
Sage,  in  the  last  century,  to  show  that 
the  phenomena  of  attraction  and  re- 
pulsion are  susceptible  of  explanation 
by  hi^  hypothesis  of  bombardment  by 
ultra-mundane  particles,  whether  ten- 
able or  not,  has  the  great  merit  of 
being  an  attempt  to  get  rid  of  the 
dual  conception  of  the  causes  of  mo- 
tion which  has  hitherto  prevailed. 
On  this  hypothesis,  the  hammering  of 
the  ultra-mundane  corpuscles  on  the 
bob  confers  its  kinetic  energy,  on  the 
one  hand,  and  takes  it  away  on  the 
other;  and  the  state  of  potential  en- 
ergy means  the  condition  of  the  bob 
during  the  instant  at  which  the 
energy,  conferred  by  the  hammering 
during  the  one  half-arc,  has  just  been 
exhausted  by  the  hammering  during 
the  other  half-arc.  It  seems  safe  to 
look  forward  to  the  time  when  the 
conception  of  attractive  and  repulsive 
forces,  having  served  its  purpose  as  a 
useful  piece  of  scientific  scaffolding, 
will  be  replaced  by  the  deduction  of 
the  phenomena  known  as  attraction 


and  repulsion,  from  the  general  laws 
of  motion. 

The  doctrine  of  the  conservation  of 
energy  which  I  have  endeavored  to 
illustrate  is  thus  defined  by  the  late 
Clerk  Maxwell : 

"  The  total  energy  of  any  body  or 
system  of  bodies  is  a  quantity  which 
can  neither  be  increased  nor  dimin- 
ished by  any  mutual  action  of  such 
bodies,  though  it  may  be  transformed 
into  any  one  of  the  forms  of  which 
energy  is  susceptible."  It  follows 
that  energy,  like  matter,  is  indesiruci- 
iRIe  and  mgenerable  in  nature.  The 
Ijlienomenal  world,  so  far  as  it  is 
material,  expresses  the  evolution  and 
involution  of  energy,  its  passage  from 
the  kinetic  to  the  potential  condition 
and  back  again.  Wherever  motion 
of  matter  takes  place,  that  motion  is 
effected  at  the  expense  of  part  of 
the  total  store  of  energy. 

Hence,  as  the  phenomena  exhibi- 
ted by  living  beings,  in  so  far  as  they 
are  material,  are  all  molar  or  molec- 
ular motions,  these  are  included  un- 
der the  general  law.  A  living  body  is 
a  machine  by  which  energy  is  trans- 
formed in  the  same  sense  as  a  steam- 
engine  is  so,  and  all  its  movements, 
molar  and  molecular,  are  to  be  ac- 
counted for  by  the  energy  which  is 
supplied  to  it.  The  phenomena  of 
consciousness  which  arise,  along  with 
certain  transformations  of  energy, 
cannot  be  interpolated  in  the  series 
of  these  transformations,  inasmuch  as 
they  are  not  motions  to  which  the  doc- 
trine of  the  conservation  of  energy 
applies.  And,  for  the  same  reason, 
they  do  not  necessitate  the  using  up 
of  energy ;  a  sensation  has  no  mass 
and  cannot  be  conceived  to  be  sus- 
ceptible of  movement.  That  a  par- 
ticular molecular  motion  does  give 
rise  to  a  state  of  consciousness  is  ex- 
perimentally certain ;  but  the  how 
and  why  of  the  process  are  just  as  in- 
explicable as  in  the  case  of  the  com- 
munication of  kinetic  energy  by  im- 
pact. 

When  dealing  with  the  doctrine  of 
the  ultimate  constitution  of  matter, 
we  found  a  certain  resemblance  be- 


IN  THE  LAST  HALF-CENTURY. 


21 


|-ine  of 
latter, 
:e  be- 


tween the  oldest  speculations  and 
the  newest  doctrines  of  physical  phi- 
losophers. But  there  is  no  such  re- 
semblance between  the  ancient  and 
modern  views  of  motion  and  its 
causes,  except  in  so  far  as  the  concep- 
tion of  attractive  and  repulsive  forces 
may  be  regarded  as  the  modified  de- 
scendant of  the  Aristotelian  concep- 
tion of  forms.  In  fact,  it  is  hardly 
loo  much  to  say  that  the  essential 
and  fundamental  difference  between 
ancient  and  modern  physical  science 
lies  in  the  ascertainment  of  the  true 
laws  of  statics  and  dynamics  in  the 
course  of  the  last  three  centuries  ; 
and  in  the  invention  of  matiiematical 
methods  of  dealing  with  all  the  con 
sequences  of  these  laws.  The  ulti- 
mate aim  of  modern  physical  science 
is  the  deduction  of  the  phenomena  ex- 
hibited by  material  bodies  from  phy 
sico-mathematical  first  principles. 
Whether  the  human  intellect  is  strong 
enough  to  attain  the  goal  set  before  it 
may  be  a  question,  but  thither  will  it 
surely  strive. 

The  third  great  scientific  event  of 
our  time,  the  rehabilitation  of  the 
doctrine  of  evolution,  is  part  of  the 
same  tendency  of  increasing  knowl- 
edge to  unify  itself,  which  has  led  to 
the  doctrine  of  the  conservation  of 
energy.  And  this  tendency,  again, 
is  mamly  a  product  of  the  increasing 
strength  conferred  by  physical  inves- 
tigation on  the  belief  in  the  universal 
validity  of  that  orderly  relation  of 
facts,  which  we  express  by  the  so- 
called  "  laws  of  nature." 

The  growth  of  a  plant  from  its 
seed,  of  an  animal  from  its  egg,  the 
apparent  origin  of  innumerable  living 
things  from  mud,  or  from  the  putre- 
fying remains  of  former  organisms, 
had  furnished  the  earlier  scientific 
thinkers  with  abundant  analogies 
suggestive  of  the  conception  of  a  cor- 
responding method  of  cosmic  evolu- 
tion from  a  formless  "  chaos  "  to  an 
ordered  world  which  might  either  con- 
tinue forever  or  undergo  dissolution 
into  its  elements  before  starting  on  a 
new  course  of  evolution.    It  is  there- 


fore no  wonder  that,  from  the  days  o£ 
the  Ionian  school  onwards,  the  view 
that  the  universe  was  the  result  of 
such  a  process  should  have  muiu- 
lained  itself  as  a  leading  dogma  uf 
philosophy.  The  emanistic  theories 
which  played  so  great  a  part  in  Nto- 
platonic  philosop'.iy  and  (Inostic  the- 
ology are  forms  of  evolution.  In  the 
seventeenth  century,  Descartes  pro- 
pounded a  scheme  of  evolution,  as  an 
hypothesis  of  what  might  have  been 
the  mode  of  origin  of  the  world,  while 
professing  to  accept  the  ecclesiastical 
scheme  of  creation,  as  an  account  of 
that  which  actually  was  its  manner  of 
commg  into  existence.  In  the  eigh- 
teenth century,  Kant  put  forth  a  re- 
markable speculation  as  to  the  origin 
of  the  solar  system,  closely  similar  to 
that  subsequently  adopted  by  Laplace 
and  destined  to  become  famous  under 
the  title  of  the  "  nebular  hypothesis." 

The  careful  observations  and  the 
acute  reasonings  of  the  Italian  geolo- 
gists of  the  seventeenth  and  eigh- 
teenth centuries;  the  speculation.s  of 
Leibnitz  in  the  "  Protoga;a  "  and  of 
Huffon  in  his  "  Theorie  de  la  Terre  ;  " 
the  sober  and  profound  reasonings  of 
Hutton,  in  the  latter  part  of  the  eigh- 
teenth century ;  all  these  tended  to 
show  that  the  fabric  of  the  earth  it- 
self implied  the  continuance  of  pro- 
cesses of  natural  causation  for  a 
period  of  time  as  great,  in  relation  to 
human  history,  as  the  distances  o£ 
the  heavenly  bodies  from  us  are,  in 
relation  to  terrestrial  standards  of 
measurement.  The  abyss  of  time 
began  to  loom  as  large  as  the  abyss 
of  space.  And  this  revelation  to 
sight  and  touch,  of  a  link  here  and  a 
link  there  of  a  practically  infinite 
chain  of  natural  causes  and  effects, 
prepared  the  way,  as  perhaps  nothing 
else  has  done,  for  the  modern  form  of 
the  ancient  theory  of  evolution. 

In  the  beginning  of  the  eighteenth 
century,  De  Maillet  made  the  fir.st 
serious  attempt  to  apply  the  doctrine 
to  the  living  world.  In  the  latter 
part  of  it,  Erasmus  Darwin,  Goethe, 
Treviranus,  and  Lamarck  took  up  the 
work  more  vigorously  and  with  better 


22 


THE  ADVANCE  OF  SCIENCE 


qualifications.  The  question  of  spe- 
cial creation,  or  evolmion,  lay  at  tiic 
liMttoin  of  \hc  fierce  (lis|ju!i.'s  which 
biolvO  ont  in  llic  l-'rcnch  AcadLiny  be- 
tween Ciivicr  and  St.-Hilaire ;  and, 
for  a  time,  llie  supporters  of  biojoyi- 
cal  evohition  were  silenced,  if  not 
answered,  by  tlie  alliance  of  the  j;reat- 


tion,  among  the  hi{;hest  forms  of  each 
;;r(iiip.  In  fact,  in  endeavoring  to 
support  these  views  he  went  a  good 
way  beyond  the  limits  of  any  cautious 
interpretation  of  the  facts  then  known. 
Althoiijih  little  acquainted  with 
bio|()>;iciil  science,  Whewell  seems  to 
have  taken  particular  pains  with  tliat 


est    naturalist  of    the    age  with  their  j  jiart  of  his  work  whi(h  deals  with  the 

ec(  lesiaslical 

phisin,  a  short-sighted  teleology,  and 


opponents.     (!atasiro- 1  history   of   geological   and   biolo;iical 


spt 


lory   oi 
.'culalio 


n  ;    and  several  chapters  of 
a  still  more  short-si;;hted  orthodoxy,  '  his  seventeenth  and  eigthleenth  books, 


Joined  forces  to  crush  evolution. 

I,yell  and  I'oulett  Scrope,  in  this 
( omitry,  resumed  the  work  of  the 
Il.dians  and  of  Ilutton  ;  and  the  for- 
mer, aided  by  a  niarvelous  power  of 
clear  exposiiion,  placed  upon  an  irre- 
fragable basis  the  truth  that  natural 
causes  are  competent  to  account  for 
all  events,  which  can  be  proved  to 
have  occurred,  in  the  course  of  the 
s(.'cular  changes  which  have  taken 
))la<i'  during  the  deposition  of  the 
sUatilicd  rocks.  'J"he  publication  of 
*'  The  principles  of  (jeology,"  in 
18^0,  consliiuted  an  ejioch  in  ge(: 
ical  science.  iJut  it  also  constituted 
an  epoch  in  the  modern  history  of  the 
doctrines  of  evolution,  by  raising  in 
the  mind  of  every  intelligoiU  reader 
this  question  ;  If  natural  causation  is 
oonqx'tenl  to  account  for  the  not-liv- 
ing part  of  our  globe,  why  should  it 
not  account  for  tiie  living  part? 

1)V  keeping  this  {|uestion  before  the 
public  for  some  thirty  years,  Lyell, 
though  the  keenest  and  most  formi- 
dable of  the  opponents  of  the  trans- 
nuitntion  theory,  as  it  was  formulated 
by  Lamarck,  was  of  the  greatest  pos- 
sible service  in  facilitating  the  recep- 
tion of  the  sounder  doctrines  of  a 
later  day.  And,  in  like  fashion, 
another  vehement  opponent  of  the 
transmutaticn  of  species,  the  elder 
Agassiz,  was  doomed  to  help  the 
cause  he  hated.  Agnssiz  not  onlv 
maintained  the  fact  of  the  progressive 
advance  in  organization  of  the  inh.nb- 
itants  of  the  earth  at  each  successive 
geological  epoch,  but  he  insisted  up- 
on the  analogy  of  the  steps  of  this 
progression  with  those  by  which  the 
embryo  advances  to  the  adult  coiuli- 


og- 1  the 


which  comprise  the  history  of  physi- 
ology, of  comparative  anatomy  and 
of  the  pallet  iological  scieiu  es,  vividly 
reproduce  the  controversies  of  the 
early  days  of  the  Victorian  epoch. 
Hut  here,  as  in  the  case  of  the  doc- 
trine of  the  conservati(Mi  of  energy, 
llie  historian  of  the  inductive  sciences 
has  no  prophetic  insight  ;  not  even  a 
suspicion  of  that  which  the  near  fut- 
ure was  to  bring  forth.  And  those 
who  still  repeat  the  once  favorite  ob- 
jection that  Darwin's  "Oiigin  of  Spe- 
cies "  is  nothing  but  a  new  version  of 
"  I'hilosophie  zoologique  "  will 
find  that,  so  late  as  1844,  Whewell 
had  not  the  slightest  suspicion  of 
Darwin's  main  theorem,  even  as  a 
logical  possibility.  In  fact,  the  pub- 
lica:i<in  of  that  theorem  by  Darwin 
and  Wallace,  in  1859,  took  all  the 
biological  world  by  surprise.  Neither 
those  who  were  inclined  toward  the 
''progressive  transmutation  "  or  "de- 
velopment"  doctrine,  as  it  was  then 
called,  nor  those  who  were  opposed 
to  it,  had  the  slightest  suspicion  that 
the  tendency  to  variation  in  living  be- 
ings, which  all  admitted  as  a  matter 
of  fact ;  the  selective  influence  of  con- 
ditions, which  no  one  could  deny  to 
be  a  matter  of  fact,  when  his  atten- 
tion was  drawn  to  the  evidence;  and 
the  occurrence  of  great  geological 
changes  which  also  was  matter  of 
fact;  could  be  used  as  the  only  nec- 
essary postulates  of  a  theory  of  the 
evolution  of  plants  and  animals  which, 
even  if  not,  at  once,  conqDetent  to  ex- 
jilain  all  the  known  facts  of  biological 
science,  could  not  be  shown  to  be  in- 
consistent with  any.  So  far  as  biol- 
ogy is  concerned,  the  publication  of 


IN    TlIK   LAST   IIALF-Cr.NTURV. 


23 


IS  of 
ooks, 
)liysi- 
■  ;iml 
ivully 
[  the 
potli. 
(loc- 

KlJiV, 

ieiiccs 
.'vcn  a 
ar  ful- 
ihosc 
10   ob- 
A  Spe- 
^ioii  of 
"    will 
[hcwcll 
n    of 
as    a 
puh- 
iiwin 
1   the 
oiilier 
the 
"  clo- 
the n 
)p(>.sed 
that 
nj;  be- 
lli a  tter 
f  coii- 
eny  to 
alten- 
and 
llogical 


)i 


Iter 


of 

\\  iiec- 

)f  the 

ihich, 

to  ex- 

;ical 

ibe  in- 

biol- 

lioii  of 


O! 


the  '•Oriq;in  of  Sprcics,"  for  the  first 
time,  put  the  iloctriiiu  of  evolmioti,  m 
its  application  to  livinj;  thini;s,  upon 
a  soniKJ  scicutilic  foundation.  It  be- 
came an  instrument  of  investigation, 
and  in  no  liands  did  it  prove  more 
brilii.intly  profitable  than  in  those  of 
hirwin  iiim^i'lf.  His  publieaiions  on 
the  elTects  of  domeslieaiion  in  plants 
ami  animals,  r)n  the  inlliieiice  of  (TOSS- '  Conum-nt  on    th.it    LMcat   inulorlakin^ 


gt'oIo;;ist  and  tlie  physicist,  whatever 
that  ni.iy  be. 

Kvolution  as  a  philoso])hical  doc- 
trine applicabli;  to  ail  pluMmmcna, 
wlu-tliLT  physical  or  mental,  wliclhcr 
manifested  by  material  aionis  or  by 
men  in  society,  has  been  de.dt  with 
sysli'inatically  in  the  '•  Syntlieiio  Phi- 
losojihy"  of     Mr.     Herbert     Spencer. 


ft-rtili 


i/ation,  on  Howers  as  or;: 


ins  for '  would  not  be  in   |)lace   here.      I    men- 
clYeclin:jj  such  fertilization,  on   insec*  j  tion  it  because,  so  far  as  1  Know,  it  is 


the  first  attempt  to  deal,  on  scientific 
principles,  with  modern  scientilic  facts 


and 


speculations. 


For  the  "  I'liilo- 


opine  positive 


of  M.    Comte 


tivoroiis    plants,    on  the    motions    of 

plants,  pointed  out  the  routes  of    ex- 
ploration which  have  since   been    fol- 

loweil   bv   hosts  of  iiujuirers,   lo   the 

great  prolit  of  scienc". 

Darwin  found  the  bfoloijical    world 

a  more  than  siilTi  iiMit  field    for  even 

his  f^real  powers,  and  left   the   cosnu- 

cal   part    of    the    doctrine    to    otheis. 

N  >:  iiri'h  has  been  add-'d  to  the  nel)- 

ular  hypotlK'sis,  since  the  time  of   La 

place,  exce|)t  that  the  attempt  to  show 

(I'^iinst  that  hvpothesis)  that  all  neb- 

11!. e  are   star   clusters,  has   been    nn't 

l)y  the  spectroscopic  proof  of  the  f;as 

cons    condition     of    some    of    th<'m. 

Moreover,   physicists  of   the   present 

generation   appear  now  to  accept  the 

secular  cooliu'jj  of   the  earth,  which  is 

one  of  the  corollaries  of   that  liyj)oih- 

esis.     in    fad,    attempts    have    been 

made,  by  the  help  of  dedn'tioiis  from 

the  data  of   physics,  to   lay  down    an 

approximate  limit   to   the   ninnber  of 

millions  of  years  whieh  have  elapsed  !  In   the  past  iiistory  of  the    universe, 

since  the   earth  was  habitable  by  liv- j  back  to  that  point,  there  can  be  no 

ing  beini;s.      If  the   conclusions   thus  j  room  for  chance  or  disorder.     J>ut  it 

reached  should  staiul  the  test  of  fur-  '  is    ])ossible    to    raise     the     (luestion 

ther  investigation,  they  will  nndonbt-    whether  this  universe  of  simplest  mat- 

edlv  be   very  valuable.      Mut,  whether  |  ter  and  definitely    operating    enerp;v, 

which  forms  our  hvpothetica!  starting 
point,  may  not  itself  be  a  product  of 
evolution  from  a  universe  of  such  mat- 


Wltll 

,'hich  Mr.  Spencer's  system  oi  philos- 
ophy is  sometimes  compared,  though 
It  professes  a  similar  object,  is  unlorl- 
unately  permeaietl  by  a  thoroughly 
unscientilic  spirit,  aiul  its  author  had 
no  adeip  ate  acquaintance  with  the 
physical  sciences  even  of  his  own  lime. 

The  doctrine  of  evolution,  so  far  as 
the  present  physical  cosmos  is  con- 
cerned, postulates  th(;  fixity  of  the 
rules  of  operation  of  the  causes  of  mo- 
tion in  the  material  universe,  if  all 
kinils  of  matter  ate  modifications  of 
one  Kind,  and  if  all  modes  of  nio:ion 
are  derived  from  the  same  energy,  the 
orderly  evolution  of  phvsical  iiaiiire 
out  of  one  substratum  ami  one  energy 
im|)lies  that  the  rules  of  acli(jii  of  that 
energy  should  be  fixed  and  definite. 


true  or  false,  they  can  have  no  intlu- 

ence  upon   the  dv)Ctrine  of  evolution 

in  its  application  to  living  organisms. 

The  occurrence  of   successive  forms  '  ter,  in  wliich    the    manifestations    of 

of  life  ui)on  our  globe  is  an  historical    energy  were    not  definite — in    which. 


fact,  which  cannot  be  disputed  ;  and 
the  relation  of  these  successive  forms, 
as  stages  of  evolution  of  the  same 
type,  is  established  in  various  cases. 
'rhe  biologist  has  no  ineans  of  deter- 
mining the  time  over  which  the  proc- 
ess of  evolution  has  extended,  but  ac- 
cepts the  computation  of  the  physical 


fm-  example,  our  laws  of  motion  held 
good  for  some  units  and  not  for  others, 
or  for  the  same  units  at  one  time  ai.  ; 
not  at  another — and  which  would 
therefore  be  a  real  epicurean  chance- 
world  ? 

For  myself,  I  must  confess  that   [ 
find  the  air  of  this  region  of  specula- 


24 


THE  ADVANCE  OK  SCIENCE 


tion  too  rarefied  for  my  constitution, 
and  I  am  disposed  to  take  refuge  in 
"  ignoramus  et  ignorabimus." 

The  execution  of  my  further  task, 
the  indication  of  the  most  important 
achievements  in  the  several  branches 
of  physical  science  during  the  last 
fifty  years,  is  embarrassed  by  the 
abundance  of  the  objects  of  choice , 
and  by  the  difficulty  which  everyone, 
but  a  specialist  in  each  department, 
must  find  in  drawing  a  due  distinction 
between  discoveries  which  strike  the 
imagination  by  tiieir  novelty,  or  by 
their  practical  influence,  and  those 
unobtrusive  but  pregnant  observa- 
tions and  experiments  in  which  the 
germs  of  the  great  things  of  the  future 
really  lie.  Moreover,  my  limits  re- 
strict me  to  little  more  than  a  bare 
chronicle  of  the  events  which  I  have 
to  notice. 

In  physics  and  chemistry,  the  old 
boundaries  of  which  sciences  are  lap- 
idly  becoming  effaced,  one  can  hardly 
go  wrong  in  ascribing  a  primary  value 
to  the  investigations  into  the  relation 
between  the  solid,  liquitl,  and  gaseous 
states  of  matter  on  the  one  hand,  and 
degrees  of  pressure  and  of  heat  on 
the  other.  Almost  all,  even  the  most 
refractory,  solids  have  been  vaporized 
by  the  intense  heat  of  the  electric  arc ; 
and  the  most  refractory  gases  have 
been  forced  to  assume  the  liquid,  and 
even  the  solid,  forms  by  the  combina- 
tion of  high  pressure  with  intense  cold. 
It  has  further  been  shown  that  there 
is  no  discontinuity  between  these 
states — that  a  gas  passes  into  the  liq- 
uid state  through  a  condition  which  is 
neither  one  nor  the  other,  and  thai  a 
liquid  body  becomes  solid,  or  a  solid 
liquid,  by  the  intermediation  of  a  con- 
dition in  which  it  is  neither  truly  solid 
nor  truly  liquid. 

Theoretical  and  experimental  in- 
vestigations have  concurred  in  the  es- 
tablishment of  the  view  that  a  gas  is 
a  body,  the  particles  of  which  are  in 
incessant  rectilinear  motion  at  high 
velocities,  colliding  with  one  another 
and  bounding  back  when  they  strike 
the  walls  of  the  containing  vessel ; 
and,  on  this  theory,  the  already  ascer- 


tained relations  of  gaseous  bodies  to 
heat  and  pressure  have  been  shown  to 
be  deducible  from  mechanical  princi- 
ples.    Immense    improvements   have 
been  effected  in  the  means  of  exhaust- 
ing a  given  space  of  its  gaseous  con- 
tents ,  and    experimentation    on    the 
phenomena  wMch  attend  the  electric 
discharge  and   the   action   of   radiant 
heat,   within    the   extremely    rarefied 
media  thus  produced,   has  yielded  a 
great  number  of  remarkable   results, 
some  of  which  have  been  made  famil- 
iar to  the  public  by  the  Gieseler  tubes 
and  the  radiometer.     Already,  these 
investigations  have  afforded  an  unex- 
pected insight  into  the  constitution  of 
matter  and  its  relations  with  thermal 
and  electric  energy,  and  they  open  up 
a  vast   field   for   future    inquiry    into 
some  of  the  deepest  problems  of  phys- 
ics.    Other  important   steps,   in   the 
same  direction,  have  been  effected  by 
investigations  into  the  absorption  of 
radiant  heat  proceeding  from  different 
sources  by  solid,  fluid,  and  gaseous 
bodies.     And  it  is  a  curious  example 
of  the  interconnection  of  the  various 
branches   of    physical    science,    that 
some  of  the  results  thus  obtained  have 
proved  of  great  importance  in  meteor- 
ology. 

The  existence  of  numerous  dark 
lines,  constant  in  their  number  and 
position  in  the  various  regions  of  the 
solar  spectrum,  was  made  out  by 
Fraunhofer  in  the  early  part  of  the 
present  centur)',  but  more  than  forty 
years  elapsed  before  their  causes  were 
ascertained  and  their  importance  rec- 
ognized. Spectroscopy,  which  then 
took  its  rise,  is  probably  that  employ- 
ment of  physical  knowledge,  already 
won,  as  a  means  of  further  acquisi- 
tion, which  most  impresses  the  imag- 
ination. For  it  has  suddenly  and 
immensely  enlarged  our  power  of  over- 
coming the  obstacles  which  almost  in- 
finite minuteness  on  the  one  hand,  and 
almost  infinite  distance  on  the  other, 
have  hitherto  opposed  to  the  recogni- 
tion of  the  presence  and  the  condition 
of  matter.  One  eighteen-millionth  of 
a  grain  of  sodium  in  the  flame  of  a 
spirit-lamp  may  be  detected  by  this 


IN  THE   LAST  HALF-CENTURY. 


25 


dark 
and 
of  the 
by 
f  the 
forty 
were 
rec- 
then 
1  ploy- 
ready 
quisi- 
iinag- 
and 
1  over- 
jst  in- 
|1,  and 
nher, 
,ogni- 
lition 
th  of  <i 
iof   a 
this 


instrument;  and,  at  the  same  time,  it 
gives  trustworthy  indications  of  the 
material  constitution  not  only  of  the 
sun,  but  of  the  farthest  of  those  fixed 
stars  and  nebulee  which  afford  suffi 
cient  light  to  affect  the  eye  or  the 
photographic  plate,  of  the  inquirer. 

The  mathematical  and  experimental 
elucidation  of  the  phenomena  of  elec- 
tricity, and  the  study  of  the  relations 
of  this  form  of  energy  with  chemical 
and  thermal,  action,  had  made  exten- 
sive progress  before  1837.  But  the 
determination  of  the  influence  of  mag- 
netism on  light,  the  discovery  of  dia- 
magnetism,  cf  the  influence  of  crystal- 
line structure  on  magnetism,  and  the 
completion  of  the  mathematical  theory 
of  electricity,  all  belong  to  the  pres- 
ent epoch.  To  it  also  appertain  the 
practical  execution  and  the  working 
out  of  the  results  of  the  great  interna- 
tional system  of  observations  on  ter- 
restrial magnetism,  suggested  by 
Humboldt  in  1836  ;  and  the  invention 
of  instruments  of  infinite  delicacy  and 
precision  for  the  quantitative  deter- 
mination of  electrical  phenomena. 
I'he  voltaic  battery  has  received 
vast  improvements  ;  while  the  inven- 
tion of  magneto-electric  engines  and 
of  improved  means  of  producing  ordi- 
nary electricity  has  provided  sources 
of  electrical  energy  vastly  superior  to 
any  before  extant  in  power,  and  far 
more  convenient  for  use. 

It  is  perhaps  this  branch  of  physi- 
cal science  which  may  claim  the  palm 
for  its  practical  fruits,  no  less  than  for 
the  aid  which  it  has  furnished  to  the 
investigation  of  other  parts  of  the 
field  of  physical  science.  The  idea  j 
of  the  practicability  of  establishing  | 
a  communication  between  distant 
points,  by  means  of  electricity,  could 
hardly  fail  to  have  simmered  in  the 
minds  of  ingenious  men  since,  well- 
nigh  a  century  ago,  experimental 
proof  was  given  that  electric  distur- 
bances could  be  propagated  through 
a  wire  twelve  thousand  feet  lonji. 
Various  methods  of  carrying  the  sug- 
gestion into  practice  had  been  car- 
ried out  with  some  degree  of  success  ; 
but  the  system  of  electric  telegraphy, 


which,  at  the  present  time,  brings  all 
parts  of  the  civilized  world  within  a 
few  minutes  of  one  another,  originated 
only  about  the  commencenient  of  the 
epoch  under  consideration.  In  its 
influence  on  the  course  of  human  af- 
fairs, this  invention  takes  its  place 
beside  that  of  gunpowder,  which 
tended  to  abolish  the  physical  in- 
equalities of  fighting  men  ;  of  print- 
ing, which  tended  to  destroy  the  effeci 
of  inequalities  in  wealth  among  learn- 
ing men ;  of  steam  transport,  which 
has  done  the  like  for  traveling  men. 
All  these  gifts  of  science  are  aids  in 
the  process  of  leveling  up ,  of  remov- 
ing the  ignorant  and  baneful  preju 
dices  of  nation  against  nation,  provmce 
against  province,  and  class  aganist 
class;  of  assuring  that  social  order 
which  is  the  foundation  of  progress, 
which  has  redeemed  Europe  from 
barbarism,  and  against  which  one  is 
glad  to  think  that  those  who,  in  our 
time,  are  employing  themselves  in 
fanning  the  embers  of  ancient  wrong, 
in  setting  class  against  class,  and  in 
trying  to  tear  asunder  the  existing 
bonds  of  unity,  are  undertaking  a  fu- 
tile struggle.  Ti^e  telephone  is  only 
second  in  practical  importance  to  the 
electric  telegraph.  Invented,  as  it 
were,  only  the  other  daj',  it  has  al- 
ready taken  its  place  as  an  appliance 
of  daily  life.  Sixty  years  ago  the  ex 
traction  of  metals  from  their  solu- 
tions, by  the  electric  current,  was 
simply  a  highly  interesting  scientific 
fact.  At  the  present  day,  the  galva- 
no-plastic  art  is  a  great  industry ; 
and,  in  combination  with  photogra- 
phy, promises  to  be  of  endless  service 
in  the  arts.  Electric  lighting  is  an- 
other great  gift  of  science  to  civiliza- 
tion, the  practical  effects  of  which 
have  not  yet  been  fully  developed, 
largely  on  account  of  its  cost.  But 
those  whose  memories  go  back  to  the 
tinder-box  period,  and  recollect  the 
cost  of  the  first  lucifer  matches,  will 
not  despair  of  the  results  of  the  appli- 
cation of  science  and  ingenuity  to  the 
cheap  production  of  anything  for 
which  there  is  a  large  demand. 

The  influence   of   the  progress   of 


26 


THE  ADVANCE  OF  SCIENCE 


electrical  knowledge  and  invention 
upon  that  of  investigation  in  other 
fields  of  science  is  highly  remarkable. 
The  combination  of  electrical  with 
mechanical  contrivances  has  produced 
instruments  by  which,  not  only  may 
extremely  small  intervals  of  time  be 
exactly  measured,  but  the  varying 
rapidity  of  movements,  which  take 
place  in  such  intervals  and  appear  to 
the  ordinary  sense  instantaneous,  is 
recorded.  The  duration  of  the  wink 
ing  ot  an  eye  is  a  proverbial  expres- 
sion for  an  instantaneous  action  ;  but, 
by  the  help  of  the  revolving  cylinder 
and  the  electrical  marking- appara- 
tus, it  is  possible  to  obtain  a  graphic 
record  of  such  an  action,  m  wliicli,  if 
it  endures  a  second,  that  second  shall 
be  subdivided  into  a  hundred,  or  a 
thousand,  equal  parts,  and  the  state 
of  the  action  at  each  hundredth,  or 
thousandth,  of  a  second  exhibited. 
In  fact,  these  instruments  may  be 
said  to  be  time-microscopes.  Such 
ajipliances  have  not  only  effected  a 
levolution  in  physiology,  by  the  power 
of  analyzing  the  piienomena  of  mus 
cular  and  nervous  activity  which  they 
have  conferred,  but  they  have  fur- 
nished new  methods  of  measuring  the 
rate  of  movement  of  projectiles  to 
the  artillerist.  Again,  the  micro- 
phone, which  reiulers  the  minutest 
movements  audible,  and  which  ena- 
bles a  listener  to  hear  the  footfall  of 
a  lly,  has  equi])ped  the  sense  of  hear- 
ing with  the  means  of  entering  al- 
most  as  deeply  into  the  penetralia 
of  nature,  as  does  the  sense  of  sight. 

That  light  exerts  a  remarkable  in- 
fluence in  bringing  about  certain 
chemical  coinl)inations  and  decomiw- 
sitions  was  well  known  lifty  years 
ago,  and  various  more  or  less  sue- 
ctssful  attempts  to  produce  jierma- 
iiL'iit  pictures,  bv  the  help  of  that 
knowledge,  had  already  been  made. 
It  was  not  till  1839,  iiowever,  that 
practical  success  was  obtained  ;  but 
the  "  daguerreotypes  "  were  both  cum- 
brous and  costly,  and  ])Iiotograpln' 
would  never  have  attained  ils  iJiesent 
important    development   had   not   the 


paper  and  glass  for  the  silvered  plates 
then  in  use.  It  is  not  my  affair  to 
dwell  upon  the  practical  apjilication 
of  the  photography  of  the  jMesent 
day,  but  it  is  germane  to  my  purpose 
to  remark  that  it  has  furnished  a 
most  valuable  accessory  to  the  meth- 
ods of  recording  motions  and  lapse  of 
time  already  in  existence.  In  the 
hands  of  the  astronomer  and  the 
meteorologist,  it  has  yielded  means 
of  registering  terrestrial,  solar,  ])Iane- 
tary,  and  stellar  phenomena,  indepen- 
dent ot  the  sources  of  error  attendant 
on  ordinary  observation ;  in  the 
hands  of  the  physicist,  not  only  does 
It  record  spectrf)scopic  phenomena 
with  unsurpassable  ease  and  precis- 
ion, but  It  has  revealed  the  existence 
of  rays  iiavmg  powerful  chemical 
energy,  or  beyond  the  visible  limits 
of  either  end  of  the  spectrum  ;  while, 
to  the  naturalist,  it  furnishes  the 
means  by  which  the  forms  of  many 
highly  complicated  objects  mav  be 
represented,  without  that  possibri'y 
of  error  which  is  inherent  in  the  work 
of  the  draughtsman.  In  fact,  in 
many  cases,  the  stern  impartiality  of 
photography  is  an  objection  to  its  em- 
ployment :  it  makes  no  distinction 
between  the  important  and  the  un- 
important ;  and  hence  photograplis 
of  dissections,  for  example,  are  rarely 
so  useful  as  the  work  of  a  draughts- 
man who  is  at  once  accurate  and  in- 
telligent. 

Tlie    determination    of    the    exist- 
ence of  a   new    planet,   Neptune,    fnr 
beyond  the  previously  known  bounds 
of  the  solar  system,   by  mathematical 
deduction  from  the  facts  of  ]X'rturba- 
tion  ;  and  the  immediate  confirmation 
i  of   that    determination,    111     the    year 
1846,  by  observers   who  turned  their 
i  telescopes  into  the  part   C)f    the    heav- 
I  ens  indicated  as  its  place,  constitute 
I  a  remarkable   testimony  of  nature  to 
the   validity  of   the    princqiles  of  the 
astronomy  of  our  time.      In  addition, 
so    many   new   asteroids    have     been 
'  added    to    those  which    were  already 
\  known  to  circulate  in  the  place  which 
theoretically   should   be  occupied   by 
progress     of     invention     substituted  [  a  planet,  between  Mars  and  Jupiter, 


IN  THE   LAST   IIALF-CENTURY. 


27 


ily  of 
IS  em- 
icUon 
iin- 
;raplis 
a  rely 
u_<;ht.s- 
iiul  in- 

exist- 


ihat  their  number  now  amounts  to 
between  two  and  three  hundred.  I 
liave  already  alluded  to  the  extension 
of  our  knowledge  of  the  nature  of  the 
heavenly  bodies  by  the  employment 
of  spectroscopy.  It  has  not  only 
•Jirfiwn  wonderful  light  upon  the  phy- 
.sic;d  and  chemical  conslilr.tion  of  the 
sun,  fixed  stars,  and  nebula-,  and 
comets,  but  it  holds  out  a  prospect  of 
obiaining  definite  cvitlence  as  to  tiie 
nature  of  our  so-called  elementary 
bodies. 

The  application  of  liie  generaliza- 
tions of  ihermotics  to  the  problem  of 
the  duration  of  the  earth,  and  of  de- 
ductions from  tidal  phenomena  to  the 
determination  of  the  length  of  the  day 
and  of  the  time  of  revolution  of  the 
moon,  in  pastei)orhs  of  the  history  of 
tiie  universe  ;  and  the  demonstration 
of  the  comjjetency  of  the  great  secu- 
lar changes,  known  under  the  general 
name  of  the  precession  of  the  ecjui- 
noxes,  to  cause  corresponding  modifi- 
catif)ns  in  the  climate  of  the  two  liemi- 
spheres  of  our  globe,  have  brought 
aslron.)my  in;o  intimate  relation  with 
geologv.  Geology,  in  fact,  proves 
that,  in  t!ie  course  of  the  {)ast  history 
of  tiie  earth,  the  climatic  conditions 
of  the  sain  J  region  have  been  widely 
ditTerent,  and  seeks  the  explanation 
of  ihis  important  truth  from  the  sister 
s.:iences.  'I'lie  facts  that,  in  the 
middle  of  the  Tertiary  c]K)ch,  ever- 
green trees  abounded  within  the  arc- 
tic circle  ;  and  that,  in  the  long  subse- 
quent Q  :aternary  e|:)och,  an  arctic 
climate,  with  its  ae;:ompaniment  of 
gigintic  glaciers,  obtained  in  the 
north-.'rn  hemisphere,  as  far  south  as 
Svitzeil  i:id  and  (Central  Viance,  are 
as  well  established  as  any  truths  of  the 
science 


liiit,  whether  the  explanation 


of  these  extreme  variations  in  them 


temneratnre   o 


n< 


rrth 


;"reat    par 


rt   of    tl 


can 


le 


ern    lieiuispliere   is    to  be  sought 


in  tiie  concomitant  changes  in  the  dis- 
tiibution  of   land   and  water  surfaces 


of  which 


geologv  aitords  evidence,  or 


111    astronomual    conditions,   sucli    as 


those    to   which   I    I 


lave 


referred,  is  a 


question  which  must  await  its  answer 
from  the  science  of  the  future. 


Turning  now  to  the  great  stops  in 
that  vast  progress  wiiich  the  bijlogi- 
cal  sciences  have  made  since  1037,  we 
are  met,  on  the  tlireshokl  of  our 
epoch,  wi'.h  perhaps  the  greatest  of 
all — namely,  the  promulgation  by 
Schwann,  in  1839,  of  the  generaliza- 
tion known  as  the  "cell  theory,"  lliu 
application  and  extension  of  which  by 
a  host  of  subsequent  investigators  has 
revolutionized  niori)hology,  develo])- 
ment  and  physiology.  Thanks  to  the 
immense  series  of  labors  thus  inau- 
gurated, the  following  inndamenlal 
truths  have  been  established. 

All  living  bodies  contain  sulistances 
of  closely  similar  phvsical  and  chemi- 
cal composition,  which  constitute  the 
physical  ba^is  of  life,  known  as  pro 
toi^lasm.  So  far  as  our  present 
knowledge  goes,  this  takes  its  origin 
only  from  pre-existing  i)rotopiasm. 

All  complex  living  Ijodies  consist, 
at  one  pcriotl  of  their  existence,  of  an 
aggregate  of  minute  portions  of  such 
substance,  of  similar  structure,  called 
cells,  e.ich  cell  having  its  own  life  in- 
dependent of  the  others,  though  in- 
lluenced  by  them. 

All  the  morphological  characters  of 
animals  and  plants  are  the  results  of 
the  mode  of  multiplication,  growili, 
and  structural  metamorphosis  of  these 
cells,  considered  as  morphological 
units. 

All  the  physiological  actixities  of 
animals  and  jjlants — assimilation,  se- 
cretion, excretion,  motion,  generation 
— are  the  expression  of  ilu-  activities 
of  the  cells  considered  as  physiologi- 
cal units.  Kach  individual,  among 
the  higher  animals  and  plants  is  a 
synth(;sis  of  millions  of  subordinate 
individualities.  Its  individuality, 
therefore,  is  tliat  of  a  '■civiuis"in 
the  ancient  sense,  or  that  of  the  Le- 
\iathan  of  I  lokbes. 


m 


Th 


'I'liere   is   no   absolute  line   of    de- 
arkation  between  animals  and  jikinis. 


e  intimate  stru.  iir 


Hid  liie  mooes 


of  change,  in  the  cells  of  the  two  are 
fundamental  I V  the  same.  Moreover, 
the  higher  forms  are  evolved  from 
lower,  in  the  cnuise  of  their  develop- 
ment, by  analogous  processes  of  dlf- 


^8 


THE  ADVANCE  OF  SCIENCE 


ferentiatio*,  coalescence,  and  reduc- 
tion in  both  the  vegetable  and  the 
animal  worlds. 

At  the  present  time,  the  cell  theory, 
in  consequence  of  recent  investiga- 
tions into  the  structure  and  metamor- 
phosis of  the  "  nucleus,"  is  under- 
going a  new  development  of  great 
significance,  which,  among  other 
things,  foreshadows  the  possibility  of 
the  establishment  of  a  physical  theory 
of  heredity,  on  a  safer  foundation 
than  those  which  Buffon  and  Darwin 
have  devised. 

The  popular  belief  in  abiogenesis, 
or  the  so-called  "  spontaneous  "  gen 
eration   of  the  lower  forms  of  life, 
which  was  accepted  by  all  the  philoso- 
phers of   antiquity,    held  its   ground 
down  to  the  middle  of  the  scenteenth 
century.       Notwithstanding   the   fre- 
quent citation  of  the  phrase,  wrong- 
fully attributed  to  Harvey,    "  Omne 
vivum  ex  ovo,"  that  great  physiolo- 
gist believed  in  spontaneous  genera-  j 
tion  as  firmly  as  Aristotle  did.     And 
it  was  only  in   the  latter  part  of  the 
seventeenth  century,  that    Redi,   by 
simple  and  well-devised  experiments, 
demonstrated  that,  in  a  great  number 
of    cases  of    supposed   sjiontaneous 
generation,  the  animals  which  made 
their  appearance  owed  their  origin  to 
the  ordinary  process  of  reproduction, 
and  thus  shook  the  ancient  doctrine 
to  its  foundations.     In  the  middle  of 
the  eighteenth  century,  it  was  revived, 
in    a   new    form,    by    Needham    and 
liufifon ;    but     the      experiments     of 
Spallanzani  enforced  the  conclusions 
of  Redi,  and  compelled  the  advocates 
of  the  occurrence  of  spontaneous  gen- 
eration to  seek  evidence  for  their  hy- 
pothesis   only   among   the    parasites 
and   the  lowest  and  minutest  organ- 
isms.     It   is  just   fifty  years    since 
Schwann     and   others     proved    that, 
even  with   respect  to  them,  the  sup- 
posed  evidence  of   abiogenesis   was 
untrustworthy. 

During  the  present  epoch,  the  ques- 
tion, wiielher  living  matter  can  be 
produced  in  any  other  way  than  by 
the  physiological  activity  of  other  liv- 
ing matter,  has  been  discussed  afresh 


with   great   vigor;  and   the   problem 
has  been  investigated  by  experimental 
methods  of  a  precision  and  refinement 
unknown    to    previous   investigators. 
The  result  is  that  the  evidence  in  fa- 
vor of  abiocrenesis  has  uttcrlv  broken 
down,  in  every  case   which  has  been 
properly  tested.     So  far  as  the  lowest 
and    minutest    organisms    are    con- 
cerned, it  has  been  proved  that  they 
never  make  their  appearance,  if  those 
precautions  by  which  their  germs  are 
certainly  excluded   are  taken.     And, 
in    regard    to    parasites,   every   case 
which  seemed   to  make  for  their  gen- 
eration from  the  substance  of  the  ani- 
mal, or  plant,   which  they  infest  has 
been   proved   to  have  a  totally  differ- 
ent  significance.     Whether  not-living 
matter  may  pass,  or  ever  has,  under 
any    conditions,   passed    into   living 
matter,  without  the  agency  of  pre-ex- 
isting   living   matter,    necessarily   re- 
mains an  open  question  ;  all  that  can 
be   said   is  that  it  does  not  undergo 
this  metamorphosis  under  any  known 
conditions.     Those    who  take  a  mo- 
nistic view  of  the  physical  world  may 
fairly    hold    abiogenesis   as   a   pious 
opinion,    supported   by   analogy   and 
defended  by  our  ignorance.     P5ut,  as 
matters  stand,  it  is  equally  justifiable 
to  regard  the  physical  world  as  a  sort 
of  dual  monarchy.     The  kingdoms  of 
living  matter   and   of  not-living  mat- 
ter  are   under  one   system  of   laws, 
and   there  is  a  perfect  freedom  of  ex- 
change and  transit  from  one  to  the 
other.     But    no   claim    to   biological 
nationality  is  valid  except  birth. 

In  the  department  of  anatomy  and 
development,  a  host  of  accurate  and 
patient  inquirers,  aided  by  novel 
methods  of  preparation,  which  enable 
the  anatomist  to  exhaust  the  details 
of  visible  structure  and  to  reproduce 
them  with  geometrical  precision,  have 
investigated  every  important  group.of 
living  animals  and  plants,  no  less  than 
the  fossil  relics  of  former  faunae  and 
floras.  An  enormous  addition  has 
thus  been  made  to  our  knowledge,  es- 
pecially of  the  lower  forms  of  life,  and 
it  may  be  said  that  morphology,  how- 
ever inexhaustible  in  detail,  is   com- 


IN  THE   LAST   HALF-CENTURY. 


29 


plete  in  its  broad  features.  Classifi- 
cation, which  is  merely  a  convenient 
summary  expression  of  morphological 
facts,  has  undergone  a  corresponding 
improvement.  The  breaks  which  for- 
merly separated  our  groups  from  one 
another,  as  animals  from  plants,  ver- 
tebrates ♦from  invertebrates,  crypto- 
gams from  phanerogams,  have  either 
been  filled  up,  or  shown  to  have  no 
theoretical  significance.  The  ques- 
tion of  the  position  of  man,  as. an  ani- 
mal, has  given  rise  to  much  disputa- 
tion, with  the  result  of  proving  that 
there  is  no  anatomical  or  develop- 
mental character  by  which  he  is  more 
widely  distinguished  from  the  group 
of  animals  most  nearly  allied  to  him, 
than  they  are  from  one  another.  In 
fact,  in  this  particular,  the  classifi- 
cation of  Linnceus  has  been  proved  to 
be  more  in  accordance  with  the  facts 
than  those  of  most  of  his  successors. 

The  study  of  man,  as  a  genus  and 
species  of  the  animal  world,  conduct- 
ed with  reference  to  no  other  consid- 
erations than  those  which  would  be 
admitted  by  the  investigator  of  any 
other  form  of  animal  life,  has  given 
rise  to  a  special  branch  of  biology, 
known  as  anthropology,  which  has 
grown  with  great  rapidity.  Numer- 
ous societies  devoted  to  this  portion 
of  science  have  sprung  up,  and  the 
energy  of  its  devotees  has  produced 
a  copious  literature.  The  physical 
characters  of  the  various  races  of  men 
have  been  studied  with  a  minuteness 
and  accuracy  heretofore  unknown ; 
and  demonstrative  evidence  of  the 
existence  of  human  contemporaries  of 
the  extinct  animals  of  the  latest  geo- 
logical epoch  has  been  obtained. 
Physical  science  has  thus  been 
brought  into  the  closest  relation  with 
history  and  with  archaeology  :  and 
the  striking  investigations  which,  dur- 
ing our  time,  have  put  beyond  doubt 
the  vast  antiquity  of  Babylonian  and 
Egyptian  civilization,  are  in  perfect 
harmony  with  the  conclusions  of  an- 
thropology as  to  the  antiquity  of  the 
human  species. 

Classification  is  a  logical  process 
which    consists    in   putting  together 


those  things  which  are  like  and  keep- 
ing asunder  those  which  are  unlike  ; 
and  a  morphological  classification,  of 
course,  takes  note  only  of  morpho- 
logical likeness  and  unlikeness.  So 
long,  therefore,  as  our  morphological 
knowledge  was  almost  wholly  confined 
to  anatomy,  the  characters  of  grou])s 
were  solely  anatomical  ;  but  as  the 
phenomena  of  embryology  were  ex- 
plored, the  likeness  and  unlikeness  of 
individual  development  had  to  be  ta- 
ken into  account ;  and,  at  present,  the 
study  of  ancestral  evolution  introduces 
a  new  element  of  likeness  and  unlike- 
ness which  is  not  only  eminently  de- 
serving of  recognition,  but  must  ulti- 
mately predominate  over  all  others. 
A  classification  which  shall  represent 
the  process  of  ancestral  evolution  is, 
in  fact,  the  end  which  the  labors  of 
the  philosophical  taxonomist  must 
keep  in  view.  But  it  is  an  end  which 
cannot  be  attained  until  the  progress 
of  palaeontology  has  given  us  far  more 
insight  than  we  yet  possess,  into  the 
historical  facts  of  the  case.  Much  of 
the  speculative  "  phylogeny,"  which 
abounds  among  my  present  contempo- 
raries, reminds  me  very  forcibly  of  the 
speculative  morphology,  unchecked 
by  a  knowledge  of  development,  which 
was  rife  in  my  youth.  As  hypothe- 
sis, suggesting  inquiry  in  this  or  that 
direction,  it  is  often  extremely  useful ; 
but,  when  the  product  of  such  spec- 
ulation is  placed  on  a  level  with 
those  generalizations  of  morphological 
truths  which  are  represented  by  the 
definitions  of  natural  groups,  it  tends 
to  confuse  fancy  with  fact  and  to  cre- 
ate mere  confusion.  We  are  in  drtU- 
ger  of  drifting  into  a  new  "  Natur-Phil- 
osophie  "  worse  than  the  old,  because 
there  is  less  excuse  for  it.  Boyle  did 
great  service  to  science  by  his  "Scep- 
tical Chemist,"  and  I  am  inclined 
to  think  that,  at  the  present  day,  a 
"sceptical  biologist  "  might  exert  an 
equally  beneficent  influence. 

Whoso  wishes  to  gain  a  clear  con- 
ception of  the  progress  of  physiology, 
since  1837,  will  do  well  to  compare 
Miiller's  "  Physiology,"  which  ai> 
peared  in  1835,  and  Drapiez's  edition 


30 


THE  ADVAN'CE  OF  SCIENCE 


of  Richard's  "  Nouveaux  EMments 
de  IJotanique,"  publislied  in  1837, 
with  any  of  the  present  hand-books 
of  animal  and  vegetaljle  physiology. 
Miiller's  work  was  a  masterpiece,  un- 
surpassed since  the  time  of  Haller, 
and  Richard's  book  enjoyed  a  great 
reputation  at  the  lime  ;  but  their  suc- 
cessors transport  one  into  a  new 
world.  'I'liat  which  cliaracterizes  the 
new  physiology  is  that  it  is  permeated 
by,  and  indeed  based  upon,  concep- 
tions which,  though  not  wholly  alt- 
sent,  are  but  dawning  on  the  minds 
of*  the  older  writers. 

Modern    physiology   sets   forth   as 
its  chief  ends  :  Firstly,  the  ascertain- 


great  functions  of  assimilation,  respi- 
ration, secretion,  distribution  of  nu- 
triment, removal  of  waste  products, 
motion,  sensation,  and  reproduction 
are  performed  ;  while  the  operation 
of  the  nervous  system,  as  a  regulative 
apparatus,  which  influences  the  orig- 
ination and  the  transmi*ioii  of 
manifestations  of  activity,  either  with- 
in itself  or  in  other  organs,  lias  been 
largely  elucidated. 

1  have  pointed  out,  in  an  earlier 
part  of  this  chapter,  that  the  history 
of  all  branches  of  science  proves  that 
they  must  attain  a  considerable  stage 
of  development  before  they  yield 
practical  "  fruits  "  ;    and   this  is  emi- 


ment  of  the   facts  and  ciMulitions  of   nently  true  of  physiology.     It  is  only 


cell-life  in  general.  Secondly,  in 
composite  organisms,  the  analysis  of 
the  functions  of    organs  into  those  of 


within  the  present  epoch,  that  physi- 
ology and  chemistry  have  reached 
the  point  at  which  they  could  offer  a 


the  cells  of  which  they  are  composed.  I  scientific  foundation  to  agriculture; 
Thirdly,  the  explication  of  the  pro- 1  and  iL  is  only  within  the  present 
cesses  by  which  this  local  cell-life  is  i  epoch,  that  zoology  and  physiology 
directly,  or  indirectly,  controlled  and  1  have  yielded  any  very  great  aid  to 
brought  into  relation  witk  the  life  of  pathology  and  hygiene.  Ikit  within 
the  rest  of  the  cells  which  compose  the  '  that  tune,  they  have  already  rendered 


organism 


Fourthly,    the    investiga- 
tion of   the  phenomena  of  life  in  gen- 
eral, on  the  assumption  that  the  phy- 
sical   and   chemical  processes  which 
take  place   in    the  living  body  are  of 
the  same  order  as  those  which  take 
place  out   of  it;   and    that   whatever 
energy  is  exerted    in   producing  such 
phenomena  is  derived  from  the  com- 
mon stock  of  energy  in  the  universe. 
In  the  fifth  place,  modern  physiology 
investigates  the  relation  between  phy- 
sical   and   psychical    phenomena,   on 
the  assumption  that  molecular  changes 
in  definite  portions  of  nervous  matter 
stand    in   the    relatioi     of    necessarv 
antecedents  to  definite    mental  states 
and     operations.      The   work    which 
has  been  done  in  each  of  the    direc- 
tions  here    indicated  is  vast,  and  the 
accumulation     of     solid    knowledge, 
which  has  been  effected,  is  correspond- 
ingly great.     For  the  first  time  in  the 
history  of   science,    physiologists  are 
now  in  the  position  to  say  that  they 
have   arrived  at  clear   and    distinct, 
though   by  no  means   complete,  con- 
ceptions of  the  manner  in  which  the 


highly  important   services   by  the  ex- 
ploration of    the  phenomena  of    para- 
sitism.    Not   only  have  the  history  of 
the     animal     parasites,    such    as   the 
tapeworms   and    the    trichina,    which 
infest   men  and  animals,  with  deadly 
results,  been  cleared  up  by  means  of 
experimental    investigations,  and  effi- 
cient  modes   of   prevention   deduced 
from    the     data    so    obtained;     but 
the  terrible  agency  of   the    parasitic 
fungi  and  of  the  infinitesimally  minute 
microbes,    which    work    far    greater 
havoc    among    plants    and    animals, 
has    been    brought    to    light.      The 
"particulate"   or    "germ"  theory  of 
disease,    as  it   is   called,    long   since 
suggested,  has  obtained  a  firm  founda- 
tion, in  so  far  as  it  has    been    proved 
to  be  true  in    respect  of   sundry  epi- 
demic  disorders.     Moreover,    it   has 
theoretically     justified     prophylactic 
measures,  such  as  vaccination,  which 
formerly  rested  on  a  merely  empirical 
basis ;  and  it   has   been  extended  to 
other  diseases  with  excellent  results. 
Further,  just  as  the  discovery  of    the 
cause  of  scabies  proved  the  absurdity 


IN  THE   LAST   IIALF-CENIURV. 


31 


lion,  respi- 
ion  of   nu- 

products, 
production 

operation 
.  regulative 
:s  tiie  orij;- 
ni!«ion  of 
either  witli- 
,,  has  been 

an    earlier 
the   history 
proves  that 
:ral>le  stage 
they    yield 
this  is  enii- 
It  is  only 
,  that  physi- 
ve    reached 
ould  offer  a 
agriculture ; 
:he     present 
.    physiology 
reat    aid    to 
l)Ut   within 
idy  rendered 
s  "by  the  ex- 
en  a  of    para- 
he  history  of 
uch    as   the 
hlnn,    which 
with  deadly 
by  means  of 
ms,  and  effi- 
on   deduced 
ained;     but 
lie    i)arasitic 
|nally  minute 
far    greater 
d     animals, 
[light.      The 
"  theory  of 
long   since 
Ifinn  founda- 
een    proved 
sundry  epi- 
iver,    it   has 
prophylactic 
fation,  which 
ly  empirical 
[extended  to 
ent  results, 
very  of   the 
e  absurdity 


of  many  of  the  old  prescriptions  for 
the  prevention  and  treatment  of  tiiat 
disease  ;  so  the  discovery  of  the  cause 
of  splenic  fever,  and  other  such  mala- 
dies, has  given  a  new  direction  to 
prophylactic  and  curative  measures 
against  the  worst  scourges  of  human- 
ity. Unless  the  fanaticism  of  philo- 
zoic  sentiment  overpowers  the  voice 
of  phiianthnjpy,  and  the  love  of  dogs 
and  cats  supersedes  that  of  one's 
neighbor,  the  progress  of  experimen- 
tal physiology  and  pathology  will,  in- 
dubitably, in  course  oi  time,  place 
medicine  and  hygiene  upf)n  a  rational 
basis.  Two  centuries  ago  Kngland 
"was  devastated  by  the  plague ;  clean- 
liness and  common-sense  were 
enough  to  free  us  from  its  ravages. 
One  century  since,  sniall-pox  was 
almost  as  great  a  scourge;  science, 
tiiough  working  empirically,  and  al- 
most in  the  dark,  lias  reduced  that 
evil  to  relative  iiisignilicance.  At 
tiie  present  time,  science,  working  in 
tiie  light  of  clear  knowledge,  has 
attacked  splenic  fever  and  has  beaten 
It  ;  it  is  attacking  hvdrophobia  with 
no  mean  j^roinise  of  success  ;  sooner 
or  later  it  will  deal,  in  the  same  way, 
with  diphtheria,  typhoid  and  scarlet 
fever.  To  one  who  has  seen  half  a 
street  swept  clear  of  iis  children,  or 
has  lost  his  own  by  these  horrible 
l^estilences,  passing  one's  offsprmg 
through  the  fire  to  Moloch  seems 
humanity,  compared  with  the  pro- 
l)osal  to  deprive  them  of  half  tlieir 
chances  of  health  and  life  because 
of  tiie  discomfort  to  dogs  and  cats, 
rabbits  and  frogs,  which  may  be  in- 
volved in  the  search  for  means  of 
guarding  them. 

An  immense  extension  has  been 
effected  in  our  knowledge  of  the  dis- 
tnbution  of  plants  and  animals  ;  and 
the  elucidation  of  the  causes  which 
have  brought  about  that  distribution 
has  been  greatly  advanced.  The 
establishment  of  meteorological  ob- 
servations by  all  civilized  nations, 
has  furnished  a  solid  foundation  to 
climatology;  while  a  growing  sense 
of  the  importance  of  the  influence  of 


a  wholesome  check  to  the  tendency 
to  overrate  the  influence  of  climate 
on  distribution.  Kxpeditions,  such 
as  that  of  t'he  "  Challenger,"  equi|)ped, 
not  for  geographical  ex[)lorati()n  and 
discovery,  but  for  the  purpose  of 
throwing  light  on  problems  of  physi- 
ca'  and  biological  science,  have  been 
sent  out  by  our  own  and  other  (lov- 
ernments,  and  have  obtained  stores 
of  information  of  the  greatest  value. 
P'or  the  first  time  we  are  111  ]iosscs- 
sion  of  something  like  precise  knowl- 
edge of  the  physical  features  of  the 
deep  seas,  and  of  the  living  popula- 
tion of  the  fioor  of  the  ocean.  The 
careful  and  exhaustive  studv  of  the 
phenomena  presented  by  the  accumu- 
lations of  snow  and  ice,  in  polar  and 
niountamous  regions,  which  has  taken 
l^lace  in  our  time,  has  not  only  re- 
vealed to  the  geologist  an  agent  of 
denudation  and  transport,  which  lias 
slowly  and  cpiietly  produced  elTects, 
formerly  confidently  referred  to  dilu- 
vial catastrophes,  but  it  has  snggesled 
nmv  methods  of  accounting  for  vari- 
ous puz/.ling  facts  of  distribution. 

Palaeontology,  which  treats  of  the 
exinici  forms  of  life  and  their  succes- 
sion and  distribution  upon  our  globe, 
H  branch  of  science  which  could 
hardly  be  said  to  exist  a  century  ago, 
has  undergone  a  wonderful  develop- 
ment in  our  epoch.  In  some  groujjs 
of  animals  and  plants,  the  extinct 
representatives,  already  known,  are 
more  numerous  and  important  than 
the  living.  There  can  be  no  doubt 
that  the  existing  Fauna  and  Flora  is 
but  the  last  term  of  a  long  series  of 
equally  numerous  contemporary  spe- 
cies, which  have  succeeded  one  an- 
I  other,  bv  the  slow  and  gradual  substi- 
1  tution  of  species  for  species,  in  the 
j  vast  interval  of  time  which  haselnps"d 
I  between  the  deposition  of  the  earliest 
fossiliferous  strata  and  the  present 
day.  There  is  no  reasonable  gifumd 
for  believing  that  the  oldest  remains 
yet  obtained  carry  us  even  near  the 
beginnings   of   life.     The    impressive 


warnings  of  Lyell  against  hasty  spec- 
ulations,   based    upon     negative    evi- 
the  "struggle  for  existence"  affords  dence,  have  been  fully  justified  ;  lime 


'tots' 


32 


THE  ADVANCE  OF  SCIENCE 


after   time,    highly    organized    types 
have  been  discovered  in   formations 
of  an  age  in  which  the  existence  of 
such  forms   of   life   had   been   confi- 
dently   declared    to    be    impossible. 
The  western  territories  of  the  United 
States  alone  have  yielded  a  world  of 
extinct  animal   forms,  undreamed  of 
fifty  years  ago.     And,  wherever  suffi- 
ciently numerous  series  of  the  remains 
of   afiy  given  group,   which   has   en- 
dured for  1   long  space  of  time,  are 
carefully  examined,  their  morpholog- 
ical relations  are  never  in  discordance 
with  the  requirements  of  the  doctrine 
of  eTolutioiT,  and  ofteil  afford  convinc- 
ing evidence  of  it.     At  the  same  time, 
it  has  been  shown  that   certain  forms 
persist  ^wilh  very  little   change,  from 
the   oldest  \6  the  newest-  fossihferous 
formations ;  and  thus  show  that  pro- 
gressive development  is  a  contingent, 
and    not   a  necessary    result,  of   the 
nature  of  living  matter. 

Geology  is,  as  it  were,  the  biology 
of  our  planet  as  a  whole.  In  so  far 
as  It  comprises  the  surface  configura 
tion  and  the  inner  structure  of  the 
earth,  it  answers  to  morphology ;  in 
so  far  as  it  studies  changes  of  con- 
dition and  their  causes,  it  corresponds 
with  physiology  ;  m  so  far  as  it  deals 
with  the  causes  which  have  effected 
the  progress  of  the  earth  from  its 
earliest  to  its  present  state,  it  forms 
part  of  the  general  doctrine  of  evo- 
lution. An  interesting  contrast  be- 
tween the  geology  of  the  present  day 
and  that  of  half  a  century  ago,  is  pre- 
sented by  the  complete  emancipation 
of  the  modern  geologist  from  the 
controlling  and    perverting   influence 


tal  assumption  (which  surely  is  a 
dictate  of  common-sense)  that  we 
ought  to  exhaust  known  causes  be- 
fore seeking  for  the  explanation  of 
geological  phenomena  in  causes  of 
which  we  have  no  experience.  But 
geology  has  advanced  to  its  present 
state  by  working  from  Lyell's  *  ax- 
iom ;  and,  to  this  day,  the  'record  of 
the  stratified  rocks  affords  no  proof 
that  the  intensity  or  the  rapidity  of 
the  causes  of  change  has  ever  varied, 
between  wider  limits,  than  those  be- 
tween which  the  operations  of  nature 
have  taken  place  in  the  youngest 
geological  epochs. 

An  incalculable  benefit  has  accrued 
to  geological  science  from  the  accu- 
rate and  detailed  surveys,  which  have 
now  been  executed  by  skilled  geolo- 
gists  employed  by  the   governments 
of  all  parts  of  the  civilized  world.     In 
geology,  the  study  of  large  maps  is  as 
important  as  it  is  said   to  be  in  poli- 
tics ;  and   sections,  on   a  true   scale, 
are  even  more  important,  in  so  far  as 
they  are  essential  to  the  apprehension 
of  the  extraordinary  insignificance  of 
geological  perturbations  in  relation  to 
the   whole   mass   of   our   planet.     It 
should  never  be  forgotten  that  what 
we  call    "catastrophes,"   are,    in    re- 
lation   to    the    earth,    changes,    the 
equivalents  of  which   would  be  well 
represented  by  the  development  of  a 
few  pimples,  or  the  scratch  of  a  pin, 
on   a  man's   head.     Vast   regions  of 
the   earth's    surface   remain   geologi- 
cally unknown  ;  but  the  area  already 
fairly  explored  is  many  times  greater 
than   it  was  in    1837  ;  and,  in   many 
parts    of    Europe   and     the    United 
of  theology,  all-powerful  at  the  earlier}  States,  the  structure  of  the  superficial 
date.     As  the  geologist  of  my  young  I  crust  of  the  earth  has  been  investi- 


days  wrote,  he  had  one  eye  upon  fact, 
and  the  other  on  Genesis  ;  at  present, 
he  wisely  keeps  both  eyes  on  fact  and 
ignores  the  pentateuchal  mythology 
altogether.  The  publication  of  the 
"  Principles  of  Geology "  brought 
upon  its  illustrious  author  a  period 
of  social  ostracism  ;  the  instruction 
given  to  our  children  is  based  upon 
those  principles.  Whewel!  had  the 
courage  to  attack  Lyell's  fundamen- 


gated  with  great  minuteness. 

The  parallel  between  biology  and 
geology,  which  I  have  drawn,  is 
further    illustrated    by    the    modern 


•  Perhaps  I  ought  rather  to  say  Buffon's 
axiom.  For  that  great  naturalist  and  writer 
embodied  the  principles  of  sound  geology  in 
a  pithy  phrase  of  the  Thiorie  de  la  Terre : 
"  i'our  juger  de  ce  qui  est  arriv^,  et  mfme 
de  ce  qui  arrivera,  nous  n'avons  qu'i  exam- 
iner ce  qui  arrive." 


IN  THE  LAST  HALF-CENTURY. 


33 


aX" 


iments 
d.     In 
)S  is  as 
n  poli- 
scale, 
)  far  as 
lension 
ance  of 
ition  to 
let.     It 
t  what 
in    rt;- 
s,    llie 
e  well 
nt  of  a 
a  pin, 
ons  of 
eolojii- 
Iready 
realir 
many 
lUnited 
erficial 
nvesti- 

ry  and 
Kvn,  is 
Ifiodern 


Juffon's 

writer 

3logy  in 

Terre  : 

It  meme 

exam- 


growth  of  that  branch  of  the  science 
known  as  petrology,  which  answers 
to  histology,  and  has  made  the  mi- 
croscope as  essential  an  instrument 
to  the  geological  as  to  the  biological 
investigator. 

The  evidence  of  the  importance  of 
causes  now  in  operation  has  been 
wonderfully  enlarged  by  the  study  of 
ghxcial  phenomena;  by  that  of  earth- 
quakes and  volcanoes ;  and  by  that 
of  the  efficacy  of  heat  and  cold,  wind, 
rain,  and  rivers  as  agents  of  denuda- 
tion and  transport.  On  the  other 
hand,  the  exploration  of  coral  reefs 
and  of  the  deposits  now  taking  place 
at  the  bottom  of  the  great  oceans, 
has  proved  that,  in  animal  and  plant 
life,  we  have  agents  of  reconstruction 
of  ?  potency  iiilherto  unsuspected. 

There  is  no  study  better  fitted  than 
that  of  geology  to  impress  upon  men 
of  general  culture  that  conviction  of 
the  unbroken  sequence  of  the  order 
of  natural  phenomena,  throughout  the 
duration  of  the  universe,  which  is  the 
great,  and  perhaps  the  most  impor- 
tant, effect  of  the  increase  of  natural 
knowledge. 


XL— THE    PROGRESS    OF    SCI- 
ENCE  FROM   1836  TO  1886. 

BY  GRANT  ALLEN. 

Fifty  years  ago  science  was  still  in- 
choate. Much  had  already  been  done 
by  the  early  pioneers.  The  ground 
had  been  cleared  ,  the  building  mate- 
rials had  been  in  part  provided ;  the 
foundations  had  been  duly  and  ably 
laid ;  but  the  superstructure  as  yet 
had  hardly  been  raised  a  poor  foot  or 
two  above  the  original  level.  The 
work  of  the  last  half  century  has  been 
twofold.  On  one  side  it  has  been  ac- 
cumulative merely :  new  stocks  of 
organizable  material — the  raw  bricks 
of  science — have  been  laid  up,  as 
before,  ready  to  the  call  of  the  mas- 
ter mason,  but  in  far  greater  profu- 
sion than  by  any  previous  age.  On 
the  other  side  it  has  been  directive 
and  architectonic  :  the  endless  stores 


of  fact  and  inference,  thus  dug  out 
and  shaped  to  the  hand  by  the  brick- 
makers  of  knowledge  in  a  thousand 
fields,  have  been  assiduously  built  up 
by  a  compact  body  of  higher  and 
broader  intelligences  into  a  single 
grand  harmonious  whole.  This  last 
task  forms  indeed  the  great  scientific 
triumph  of  our  epocli.  Ours  has 
been  an  age  of  firm  grasp  and  of  wide 
vision.  It  has  seen  the  downfall  of 
the  anthropocentric  fallacy.  Cosmos 
has  taken  the  place  of  chaos,  Iso- 
lated facts  have  been  fitted  and  dove- 
tailed into  their  proper  niche  ui  the 
vast  mosaic.  The  particular  has 
slowly  merged  into  the  general,  the 
general  into  still  higher  and  deeper 
cosmical  concepts.  We  live  in  aii 
epoch  of  unification,  simplification, 
correlation,  and  universality.  When 
after-ages  look  back  upon  our  own, 
they  will  recognize  that  in  science  its 
key-note  has  been  the  idea  of  unity. 

Fifty  years  ago,  there  were  many 
separate  and  distinct  sciences,  but 
hardly  any  general  conception  of 
science  at  large  as  a  single  rounded 
and  connected  whole.  Specialists 
rather  insisted  pertinaciously  on  the 
utter  insularity  of  their  own  peculiar 
and  chosen  domain.  Zoologists  \no- 
tested  with  tears  in  their  eyes  that 
they  had  nothing  to  do  with  chemistry 
or  with  physics;  geologists  protested 
with  a  shrug  of  their  shoulders 
that  they  had  nothing  to  do  with  as- 
tronomy or  with  cosmical  genesis.  It 
was  a  point  of  honor  with  each  par- 
ticular department,  indeed,  not  to 
encroach  on  the  territory  oif  depart- 
ments that  lay  nearest  to  it.  Tres- 
passers from  the  beaten  path  of  the 
restricted  science  were  prosecuted 
with  the  utmost  rigor  of  the  law. 
And  within  the  realm  of  each  separate 
study,  in  like  manner,  minor  truths 
stood  severely  apart  from  one  an- 
other :  electricity  refused  to  be  at  one 
with  magnetism,  and  magnetism  was 
hardly  on  speaking  terms  with  the  vol- 
taic current.  Organization  and  subor- 
dination of  part  to  whole  had  scarcely 
yet  begun  to  be  even  aimed  at.  The 
sciences  were  each  a  huge  congeries  of 


34 


THE  PROGRKSS  OF  SCIENCE  FROM   1836  TO   1 886. 


1^ 


heterogeneous  facts  or  unassorted 
laws:  iliev  waited  the  advent  of  their 
unknown  Newtons  to  fall  into  syste- 
matic and  organic  order. 

In  the  pride  of  our  hearts,  we  for- 
get for  tiie  nu)st  part  how  very  young 
science  still  is.     We,  who  have  seen 
that  infant   Hercules  strangling   ser- 
pents almost  from  its  very  cradle;  we 
who  have  beheld  it  grow  rapidly  un- 
der our  own  eyes  to  virile  maturity 
and    adult    robustness   of    thew    and 
muscle,  we  forget  how  new  a  power  it 
iii  in  the  worki,  and   how  feeble  and 
timid  was  its  tender  babyhood  in  the 
first  few  decades  of  the  present  cent- 
ury.    Among   the  concrete   sciences, 
astronomy,  the   eldest-born,  had   ad- 
vanced   furthest   when    our   age   was 
still  young.     It  had  reached  the  stage 
of  wide  general  laws  and  evolutionary 
aspirations.      But   geology   had   only 
just  begun  to  emerge  from  (he  earliest 
plane  of    puerile  hypothesis  into  the 
period  of  collection  and  colligation  of 
facts.     Biology,  hardly  yet  known  by 
any  better  or  truer  name  than  natural 
history,  consisted  mainly  of  a  jumble 
of  half-classified  details.     Psychology 
still    wandered    disconsolate     in    the 
misty  domain  of   the  abstr.act  meta- 
physician.    The  sciences  of  man,  of 
language,  of  societies,  of  religion,  had 
not  even   begun   to  exist.     The   an- 
tiquity of  our  race,  the  natural  genesis 
of   arts   and    knowledge,  the    origin 
of  articulate   speech,  or  of  religious 
ideas,  were  scarcely  so  much  as  de- 
batable questions.     Among   sciences 
of  the  abstract-concrete  class,  physics, 
unilluminated  by  the  clear  light  of  the 
principles  of  correlation  and  conserva- 
tion of  energy,  embraced  a  wide  and 
ill-digested     mass    of    separate     and 
wholly      unconnected      departments. 
Light  had  little  enough   to  do  with 
heat,  and  nothing  at  all  to  do  in  any 
way  with  electricity  or  sound  or  mo- 
tion   or   magnetism.     Chemistry  still 
remained  very  much  in  the  condition 
of  Mrs.  Jellaby's  cupboard.     Every- 
where scienc?  was  tentative   and   in- 
vertebrate, feeling   its  way  on  earth 
with  hesitating  steps,  trying  its  wings 
in  air  with  tremulous  fear,  in  prepara- 


tion for  the  broader  excursions  and 
wider  flights  of  the  last  three  advent- 
urous decades. 

The   great  campaign  of  the  unity 
and  uniformity  of  nature  was  the  first 
to  be  fought,  and  in   that  campiiign 
the  earliest  decisive  battle  was  wagtil 
over  the  bloody  field  of  geology.     In 
1837 — to   accept    a   purely   arbitrary 
dale  for  the  beginning  of  our  e|)(ich — 
Lyell  had  already  published  his  soI>er 
and  sensible  J'rindphs,  and   the  old 
doctrine    of     recunent     catastrophes 
and  periodical  cataclysms  was  totter- 
ing to   its  fall   in   both   hemispheres. 
Wholesale  destructions  of  faunas  and 
floras,  wholesale  creations  of  new  life- 
systems,  were  felt  to  be  out  of  keep- 
ing with  a  human  age.     Drastic  cos- 
mogonies were  going  out  of  fashion. 
But   even   the   unifoimitarianism   for 
which  Lyell  bravely  fought  and  con- 
quered, was   in   itself  but  a  scrappy 
and  piecemeal  conception  side  by  side 
with  the  wider  and  far  more  general 
views  which   fifty  years   have   slowly 
brought  to  us.     One  has  only  to  open 
the  Text  Book  of  Geology  by  Lyell's 
far    abler    modern    disciple,    Archi- 
bald Geikie,  in  order  to  see  the  vast 
advance  made  in  our  ideas  as  to  the 
world's  history  during  the  course  of 
the  last  half  centurv.     The  science  of 
the   earth's   crust   no,  longer    stands 
isolated  as  a  study  by  itself :  it  fnlls 
into  its  proper  place  in  the  hierarchy 
of  knowledge   as  the  science  of  the 
secondary    changes,   induced     under 
the   influence  of  internal  forces  and 
incident  energies,  on  the  cooling  and 
corrugated  surface  of   a  once  incan- 
descent and   more  extended   planet. 
I  know  no  better  gauge  of  the  widen- 
ing which  comes  over  the  thoughts  of 
men  with  the  process  of  the  suns  than 
to   turn    from    the   rndis   indigestaque 
moles  of  the  Principles  and  the  Elements 
(great  as  they  both  were  in  their  own 
day)  to  the  luminous,  lucid,  and  com- 
prehensive  arrangement   of   Geikie's 
splendid  and  systematic    Text  Book, 
The  one  is  an  agreeable  and  able  dis- 
sertation on  a  number  of  isolated  and 
floating  geological  facts  ;  the  other  is 
a    masterly    and    cosmically-minded 


TIIK   PKOGUESS  OF  SCIENCE  FROM    1 836  TO    I886. 


35 


In 


;)l>er 

old 
plies 
ttev- 
L-res. 

nncl 

life- 
Leep- 

cos- 
liion. 
1   for 

coii- 
•appy 
;  side 
neral 
lowly 

open 

ACU'S 

(ichi- 
;  vast 
the 
se  of 
ce  of 
Itands 
fills 
rchy 
If  the 
nder 
and 
and 
can- 
anet. 
i  den- 
ts of 
than 
taque 
ments 
own 
coin- 
kie's 
00k, 
dis- 
and 
er  is 
Inded 


account  of  the  phenomena  observable 
on  t!ic  oul.T  siicU  of  a  coolinj;  world, 
d;:Iy  Cv)'.;si(lcri(l  in  all  their  relations, 
and  ff.'.ly  co-ordinated  vilh  all  the 
chief  i>;  ults  of  all  elder  and  younger 
sis'.cr  sciences. 

Tlie  battle  of  uniformitarianism 
itself,  however,  was  but  a  passing  epi 
sodc  in  (lie  great  evolutionary  move- 
ment. That  movement  began  along 
several  distinct  lines  toward  the  close 
of  the  previous  century,  and  only  at 
last  consciously  recognized  its  own 
informing  unity  of  purpose  some 
thirty-five  years  ago.  From  another 
jioinl  of  view — in  connection  with  its 
influence  upon  thought  at  large — the 
evolutionary  crisis  has  been  treated 
elsewhere  in  this  review  by  a  philo- 
sophic thinker;  but  in  its  purely  sci- 
entific aspect  it  must  also  be  briefly 
considered  here,  forming,  as  it  does, 
the  acknowledged  mainsi^ring  of  all 
living  and  active  contemporary  sci- 
ence. 

Evolution  is  not  synonymous  with 
Darwinism.  The  whole  immensely 
exceeds  the  part.  Darwinism  forms 
but  a  small  chapter  in  the  history  of  a 
far  vaster  and  more  comprehensive 
movement  of  the  human  mind.  In 
its  astronomical  development  evolu- 
tion had  already  formulated  itself 
with  perfect  distinctness  before  the 
period  with  which  we  have  here  spe- 
cially to  deal.  The  nebular  theory  of 
Kant  and  Laplace  was  the  first 
attempt  to  withdraw  the  genesis  of 
the  cosmos  from  the  vicious  circle  of 
metaphysical  reasoning,  and  to  ac- 
count for  it  by  the  continuous  action 
of  physical  and  natural  principles 
alone.  Our  own  age  has  done  much 
to  cast  doubt  upon  the  unessential 
details  of  Kant's  rough  conception, 
but,  in  return,  it  has  made  clearer 
than  ever  the  fundamental  truth  of  its 
central  idea — the  idea  that  stars,  and 
suns,  and  solar  svstems  consist  of 
materials  once  more  diffusely  spread 
out  through  space  and  now  aggre- 
gated around  certain  fixed  and  defi- 
nite nuclei  by  the  gravitative  force 
inherent  in  their  atoms  and  masses. 
As  these  masses  or  atoms  drew  closer 


together  in  union  around  the  common 
center,  their  primitive  poicntial  crt* 
ergy  of  separation  (frankly  to  employ 
the  terminology  of  our  own  time)  was 
changed,  first  mto  the  kinetic  energy 
of  molar  motion  in  the  act  of  union, 
and  then  into  the  kinetic  energy  of 
molecular  motion  01  heat,  as  ihey 
clashed  with  one  another  in  bodily 
impact  around  the  central  core. 
Each  star,  thus  produced,  forever 
gathers  m  materials  from  its  own  out- 
lying mass,  or  from  meteoric  bodies, 
upon  its  solidifying  nucleus,  and  for- 
ever radiates  off  its  store  of  asso- 
ciated energy  to  the  hypothetical  sur- 
rounding ether.  The  fullest  expres- 
sion of  this  profound  cosmical  corn 
ception  has  been  given  in  our  owr» 
time  by  Tait  and  Balfour  Stewart, 
working  in  part  upon  the  previous  re- 
sults of  Kant,  Laplace,  the  lierschels, 
Mayer,  Joule,  Cleik  IMaxwell.  aiul 
Sir  William  Thomson.  Deeply  al- 
tered as  the  nebular  hypothesis  has 
been  by  the  modern  doctrine  of  corre- 
lation and  conservation  of  energies, 
and  by  modern  researches  into  the 
nature  of  comets,  meteors,  and  the 
sun's  envelopes,  it  still  remains  in  its 
ultimate  essence  the  original  theory 
of  Kant  and  Laplace. 

Science  has  thus,  within  the  period 
of  our  own  half-century,  exhibited  to 
us  the  existing  phase  of  the  universe 
at  large  in  the  light  of  an  episode  in 
a  single  infinite  and  picturable  drama, 
setting  out  long  since  from  a  definite 
beginning,  and  tending  slowly  to  a 
definite  end.  Other  phases,  incon- 
ceivable to  us,  may  or  may  not  possi- 
bly have  preceded  it;  yet  others, 
equally  inconceivable,  may  or  uiay 
not  possibly  follow,  lint  as  realizable 
to  ourselves,  within  our  existing  lim- 
itations, the  physical  universe  now 
reveals  itself  as  starling  in  a  remote 
past  from  a  diffuse  and  perhaps  neb- 
ulous condition,  in  which  all  the  mat- 
ter, reduced  to  a  state  of  extreme 
tenuity,  occupied  immeasurably  wide 
areas  of  space,  while  all  the  energy 
existed  only  in  the  potential  form  as 
separation  of  atoms  or  molecules; 
and  the  evidence  leads  us  to  look  foj- 


.6 


THE   TROGRESS  OF   SCILNCl-:   FROM    iS^O  TO   1886. 


ward  to  a  remote  future  when  all  the 
matter  shall  he  ag^'rcfjalcd  into  its 
narrowest  possible  limits,  while  all 
the  eiieri^y,  haviiij;  assumed  the  kinetic 
mode,  shall  have  been  radiated  off  into 
the  ethereal  medium.  Compared  to 
tl\e  inrmite  cosmical  vistas  thus  laid 
open  before  our  da/zled  eyes,  all  the 
other  scientific  expansions  of  our  age 
shrink  into  relative  narrowness  and 
iiKsij^'nificanL-e. 

As  in  the  cosmos  so  in  the  solar 
system  itsulf,  evolutionism  has  tauj,du 
us  to  rej,'ard  our  sun,  with  its  atten- 
dant planets  and  their  ancillary  satel- 
lites, all  in  their  several  orbits,  as 
owing  their  shape,  si;ie,  relations,  and 
movements,  not  to  external  desi;;n 
and  deliberate  creation,  but  to  the 
slow  and  regular  working  out  of 
physical  laws,  in  accordance  with 
which  each  has  assumed  its  existing 
weight,  and  bulk,  and  path,  and 
position. 

Geology  here  takes  up  the  evolu- 
tionary parable,  and,  accepting  on 
trust  from  astronomy  the  earth  itself 
as  a  cooling  sjiheroid  of  incandescent 
matter,  it  has  traced  out  the  various 
steps  by  which  the  crust  assumed  its 
present  form,  and  the  continents  and 
oceans  their  present  distribution. 
Lyell  here  set  on  foot  the  evolution- 
ary impulse.  The  researches  of 
Scrope,  Judd,  and  others  into  vol- 
canic and  hypogene  action,  and  the 
long  observations  of  geologists  every- 
where on  the  effects  of  air,  rain,  ice, 
livers,  lakes,  and  oceans,  have  re- 
sulted in  putting  dynamical  geology 
on  a  firm  basis  of  ascertained  fact. 
The  heated  interior  has  been  shown 
almost  with  certainty  to  consist  of  a 
rigid  and  solid  mass,  incandescent, 
hut  reduced  to  solidity  under  the 
enormous  pressure  of  superincumbent 
rocks  and  oceans.  The  age  of  the 
earth  has  been  approximately  meas- 
ured, at  least  by  plausible  guesswork  ; 
and  the  history  of  its  component 
parts  has  been  largely  reconstructed. 
Structural  and  stratigraphical  geology 
hare  reached  a  high  pitch  of  ac- 
curacy. It  is  beginning  to  be  possi- 
ble, by  convergence  of  evidences,  as 


the  American  geologists  have  shown, 
and  as  CJeikie  has  exemplilicd,  to  re- 
write in  part  the  history  of  continents 
and  oceans,  and  to  realize  each  great 
land-mass  as  an  organic  whole,  grad- 
ually evolved  in  a  ck-finite  direction 
and  growing  from  age  to  a>;c  by  reg- 
ular accretions.  VN'lnre  the  old  school 
saw  cataclysms  and  miracles,  vast 
submergences  and  sudden  elevations, 
the  new  school  sees  slow  develo|>- 
ment  and  substantial  continuity 
throughout  enormous  periods  of  sinh 
ilar  activity. 

It  would  be  itnpossible  to  pass  over 
in  silence,  in  however  brief  a  r/s//m/, 
the  special  history  of  the  glacial 
epoch  theory — a  theory  referring  in- 
deed only  to  a  single  episode  in  the 
life  of  our  planet,  but  fraught  with 
such  immense  consequences  to  plants 
and  animals,  and  toman  in  particular, 
that  it  rises  into  very  high  importance 
among  the  scientific  discoveries  of 
our  own  era.  Demonstration  of  the 
fact  that  the  recent  peiitxl  was  pre- 
ceded by  a  long  reign  rf  ice  and 
snow,  in  the  northern  and  southern 
hemispheres  alike,  we  owe  mainly  to 
the  fiery  and  magnetic  genius  of 
Agassiz ;  and  the  proof  that  this  gla- 
cial period  had  many  phases  of  hotter 
and  colder  minor  spells  has  been 
worked  up  in  marvelous  detail  by 
James  Geikie  and  other  able  c(  a<i- 
jutors.  Its  theoretic  explanation,  its 
probable  causes,  and  its  alternation 
in  the  northern  and  southern  hemi 
spheres  by  turns,  have  been  ade- 
quately set  forth  by  Croll  m  a  pro- 
foundly learned  and  plausible  hy- 
pothesis. Upon  the  glacial  epoch  de- 
pend so  many  peculiarities  in  the 
distribution  of  plant  and  animal  forms 
at  the  present  day  that  it  has  come  to 
assume  a  quite  exceptional  importance 
among  late  geological  and  biological 
theories.  Standing  at  the  very  thresh- 
old of  the  recent  period,  the  great 
ice  age  forms  the  fixed  date  from 
which  everything  in  modern  Europe 
and  America  begins — it  is  the  real 
flood  which  stands  to  the  true  story 
of  our  continent  and  our  race  in  the 
same  relation  as  the  Noachian  deluge 


THE  i'UO(;ki:ss  ov  sciknck  kkom  1836  to  1886. 


37 


stood  to  the  imagined  or  tradilional 
world  of  our  prc-scienlific  aiircstors. 
Modern  history  bejjins  with  the  gla- 
cial epocli. 

The  science  of  life  has  been  even 
more  profouiully  affected  by  the  evo- 
lutionary impulse  than  the  concrete 
sciences  of  inor<;anic  totals.  In  1837 
biolo;^y  as  such  hardly  existed  ;  zool- 
ogy and  botany,  its  separate  compo- 
nents, were  still  almost  wholly  con« 
cerned  with  minute  questions  of  clas- 
sification ;  "vital  force"  and  odicr 
unimaginable  metaphysical  entities 
were  the  sole  explanations  curremlv 
olTered  of  all  the  ])hennmena  of  plant 
and  animal  life.  IJiit  Charles  Darwin 
had  then  just  returned  from  the  cruise 
of  the  BcaglCy  and  was  revolving  slowly 
in  his  own  mind  the  observations  and 
ideas  which  blossomed  out  at  last  in- 
to the  Orif^in  of  Species.  The  germs 
of  evolutionism  were  already  in  the 
air.  Lamarck's  crude  speculations 
had  aroused  the  attention  of  all  the 
best  biological  intellects  of  the  era. 
Hefore  long  Chambers  |)ublished  the 
Vesti}:^es  of  Crealion,an(\  Herbert  Spen- 
cer was  hard  at  work  upon  the  ground- 
work of  the  System  of  Syntlietic  J'/ti- 
losophy,  'I'he  palajontological  work 
of  Agassiz,  Barraude,  Owen  and 
others,  and  the  general  advance  in 
knowledge  of  comparative  anatomy 
and  embryology,  paved  the  way  for 
the  triumph  of  the  new  ideas ;  while 
simultaneously  the  dry  bones  of  bot- 
any were  being  kindled  into  life  by  a 
younger  school  of  workers  in  many 
French  and  German  gardens  and  lab- 
oratories. With  the  appearance  of 
the  Origin  of  Species  in  1859,  the  new 
departure  definitely  began.  In  twen- 
ty years  the  whole  world  was  convert- 
ed en  bloc.  Evolution  on  the  organic 
side  has  been  chiefly  expounded  in 
England  by  Darwin,  Huxley,  Spencer, 
and  Wallace ;  and  on  the  whole, 
though  of  world-wide  acceptance,,  it 
has  been  a  peculiarly  Pmglish  move- 
ment. Hitherto,  indeed,  we  Ikitons 
have  been  remarkable  as  the  pro- 
pounders  of  the  deepest  and  widest 
scientific  generalizations :  it  is  only 
of  late  years  that  our  bookish  educa- 


tors of  the  new  school  have  conceived 
the  noble  anibition  of  turning  us  all 
into  imitation  (lermans.  > 

Life  thus  falls  into  its  proper  place 
in  the  scheme  of  things  as  due  essen- 
tiallv  to  the  secondarv  action  of  radi- 
ated  solar  energy,  intercepted  on  the 
moist  outer  crust  of  a  cooling  and 
evolving  planet.  Its  various  forms 
have  been  gradually  produc«jd,  mainly 
by  the  action  of  natural  selection  or 
survival  of  the  fittest  on  the  immi-nse 
number  of  separate  individuals  eject- 
ed from  time  to  time  by  pre-existing 
organisms.  How  the  first  organisms 
came  to  exist  at  all  we  can  as  yet  only 
conjecture  ;  to  feeble  and  unimagina- 
tive minds  the  difficulty  of  such  a  con- 
jecture seems  grotesijuely  exagger- 
ated ;  but  granting  the  existence  of  a 
prime  organism  or  grouj)  of  organisms 
plus  the  fact  of  reproduction  willvhe 
redity  and  variations,  and  the  tei. 
dency  of  such  reproduction  to  beget 
increase  in  a  geometrical  ratio,  we 
can  deduce  from  these  simple  ele- 
mentary factors  the  necessary  corol- 
lary of  survival  of  the  fijtest.with  all 
its  far-reaching  and  manxdous  impli- 
cations. Our  age  has  discovered  for 
the  first  time  the  cumulative  value  of 
the  infinitesimal.  "Many  a  little 
makes  a  mickle;"  that  was  Lyell's 
key  in  geology,  that  was  Darwin's  key 
in  the  science  of  life.  Herbert  Speii- 
cer's  Principles  of  Bio/oj^y  most  fully 
sum  up  this  whole  aspect  of  evolution 
as  applied  to  the  genesis  of  organic 
beings. 

In  1837,  the  science  of  man,  and 
the  sciences  that  gather  roimd  the 
personality  of  man,  had  scarcely  yet 
begun  to  be  dreamt  of.  l>ut  evolu 
tionism  and  geological  investigation 
have  revolutionized  our  conception  of 
our  own  species  and  of  the  ]:)lace 
which  it  holds  in  the  hierarciiy  of  the 
universe.  At  the  very  beginning  of 
our  fifty  years,  Boucher  de  Perthes 
was  already  enthusiastically  engaged 
in  grubbing  among  the  drift  of  Abbe- 
ville for  those  rudely  chipped  masses 
of  raw  flint  which  we  now  know  as 
palzeolithic  hatchets.  Lyell  and  oth- 
ers meanwhile  were  gradually  extend- 


38 


THE   PKOGRESS   OF   SCIENCE   FROM 


1 8^,6  TO 


1886. 


ing  their  ideas  of  the  age  of  our  race 
on  earth  ;  and  accumulations  of  evi- 
dence, from  bone-caves  and  loess, 
were  forcing  upon  the  minds  of  both 
antiquaries  and  geologists  the  fact 
that  man,  instead  of  dating  back  a 
mere  irille  of  six  thousand  years  or 
so,  was  really  contemporary  with  the 
mammoth,  the  cave-bear,  and  other 
extinct  quaternary  animals.  The 
mass  of  proof  J  thus  slowly  gathered 
together  in  all  parts  of  the  world  cul- 
minated at  last  in  Lyell's  epoch-mak- 
ing Antiquity  of  Man,  published  three 
years  after  Darwin's  Origin  of  Species. 
Cole'nso's  once  famous  work  on  the 
Pentateuch  had  already  dealt  a  seri- 
ous blow  from  the  critical  side  at  the 
authenticity  and  literal  truth  of  the 
Mosaic  cosmogony.  It  was  the  task 
of  Lyell  and  his  coadjutors,  like  Evans, 
Keller,  and  Christy  and  Lartet,  to 
throw  back  the  origin  of  our  race 
from  the  narrow  hmits  once  assigned 
it  into  a  dim  past  of  mimeasurable 
antiquity.  Boyd  Dawkins,  James 
Geikie,  Huxley,  Lubbock,  Pe  Mor- 
tillet,  and  Bourgeois  have  aided  m 
elucidating,  confirming,  and  extend- 
ing this  view,  which  now  ranks  as  a 
proved  truth  of  palacontological  and 
historical  science, 

Darwin's  Descent  of  Man,  published 
some  years  later,  was  an  equally  ep- 
och-making book.  Lubbock's  Frehts- 
tpric  Times,  sent  forth  in  1865,  and 
Origin  of  Cii'ilization  in  1870,  had 
familiarized  men's  minds  with  the 
idea  that  man,  instead  of  being  "  an 
archangel  ruined  ''  Jiad  really  started 
|rom  the  savage  condition,  and  had 
gradually  raised  himself  to  the  higher 
levels  of  art  and  learning.  Tylor's 
^arly  History  of  Mankind,  followed  a 
little  later  by  his  still  more  important 
work  on  Primitive  Culture,  struck  the 
first  note  of  the  new  revolution  as  a[> 
plied  to  the  genesis  of  religious  con- 
cepts. McLennan's  Primitive  Mar- 
riage directed  attention  to  the  early 
liature  and  relations  of  the  tribe  and 
family.  Wallace's  essay  on  the  Ori- 
gin of  Human  Races  and  Huxley's 
valuable  work  on  Man's  Place  in  Nat- 
ure helped  forward  the  tide  of  natu- 


ralistic explanation.  And  by  the  time 
that  Darwin  published  his  judicial 
summing  up  on  the  entire  question  of 
man's  origin,  the  jury  of  scientific 
opinion  throughout  the  world  had 
pretty  well  considered  its  verdict  on 
all  the  chief  questions  at  issue. 

The    impetus   thus   given    to    the 
sciences   which    specially   deal    with 
man,    has   been    simply  incalculable. 
Philology    has    been    revolutionized. 
Language  has  told   us  a   new  story. 
Words,  like   fossils,  have  been  made 
to   yield    up    their    implicit    secrets. 
I'rehistoric   archaeology  has  assumed 
a  fresh  and  unexpected   importance. 
The   history  of  our   race,  ever   since 
tertiary    times,    and    throughout    the 
long    secular   winters   of   the  glacial 
epoch,  has  been  reconstructed  for  us 
from    drift  and  bone-cave,  from  bar- 
row and  picture-writing,  with  singular 
ingenuity.     Anthropology  and  sociol- 
ogy have  acquired  the  rank  of  distinct 
sciences.    The  study  of  institutions  has 
reached  a  sudden  development  under 
the  hands  of  Spencer,  Tylor,  McLen- 
nan, Maine,  Freeman,  Lang,  and  Bage- 
hot.      Comparative     mytliology     and 
folklore  have  asserted  their  right  to  a 
full  hearing.     Evolutionism  has  pen- 
etrated all  the  studies  which  bear  upon 
the    divisions   of  human    life.     Lan- 
guage,    ethnography,     history,     law, 
ethics,  and  politics,  have  all  fell  the 
widening  wave  of  its  influence.    The 
idea   of  development   and   affiliation 
has  been  applied  to  speech,  to  writing, 
to   arts,  to   literature,   nay,   even   to 
such  a  detail  as  numismatics.     Our 
entire  view  of  man  and  his  nature  has 
been    reversed   and   a    totally   fresh 
meaning  has  been  given  to  the  study 
of  savage  manners,  arts,  and  ideas,  as 
well  as  to  the   results  of  antiquarian 
and  archaeological  inquiry. 

In  psychology,  the  evolutionary  im- 
pulse has  mainly  manifested  itself  in 
Herbert  Spencer,  and  to  a  less  degree 
in  Bain,  Sully,  Romanes,  Croom  Rob- 
ertson, and  others  of  their  school. 
The  development  of  mind  in  man  and 
animal  has  been  traced  pari  passu 
with  the  development  of  the  maleiial 
1  organism. 


Instinct  has  been  clcarlv 


y 


THE  PROGRESS  OF  SCIENCE  FROM    1 836  TO    1 886. 


39 


stinct 
IS  has 
iiider 
:Len- 
Bage- 
and 
to  a 
pen- 
upon 
Lan- 
law, 
L  the 
The 
ation 
iling, 
n   to 
Our 
iC  has 
fresh 
tudy 
s,  as 
arian 


ly  im- 

ilf  in 
igiee 


Rob- 
Ihool. 
and 
hissu 
[urial 
Lavlv 


separated  from  reason:  the  working  I  in   this   direction.     They   recognized 
of  intelligence   and  of  moral  feeling  I  that  heat  was  a  mode  of  motion,  and 


has  been  recognized  in  horse  and 
dog,  in  elephant  and  parrot,  in  bee 
and  ant,  in  snail  and  spider.  The 
genesis  and  differentiation  of  nervous 
systems  have  been  fully  worked  out. 
Here  Maiidsley  has  carried  the  prac- 
tical implications  of  the  new  psychol- 
ogy into  the  do»iain  of  mental  pathol- 
ogy, and  Kerrier  has  thrown  a  first 
ray  of  light  upon  the  specific  functions 
of  jjortions  of  the  brain.  Galton's 
Hcrciiitary  Genius  and  other  works 
have  also  profoundly  influenced  the 
thought  of  the  epoch  :  while  Bastian, 
Clifford,  Jevons,  and  others  have  car- 
ried the  same  impulse  with  marked 
success  into  allied  lines  of  psycholog- 
ical research. 

But  the  evolutionary  movement  as 
a  whole  sums  itself  up  most  fullv  of 
all  in  the  ])erson  and  writings  of  Her- 
bert Spencer,  whose  active  life  almost 
exactly  covers  and  coincides  with  our 
half-centurj'.  It  is  to  him  that  we 
owe  the  word  evolution  itself,  and  the 
ge"°'al  concejit  of  evolution  as  a 
sing,  all-pervading  natural  process. 
He,  too,  has  traced  it  out  alone 
through  all  its  modes,  from  sun  and 
star,  to  plant  and  animal  and  human 
product.  In  his  First  Frinciplcs,  he 
has  developed  the  system  in  its  widest 
and  most  abstract  general  aspects. 
In  the  Principles  of  Bioloti^y  he  has  ap- 
plied it  to  organic  life  ;  in  the  Prind- 
ph's  of  Psycholo!^}' \.o  mind  and  habit : 
in  tlie  Principles  of  Sociology  to  socie- 


Rumford  went  so  far  as  to  observe 
that  the  energy  generated  by  a  give?' 
amount  of  hay  burnt  iu  an  engine 
might  be  measured  against  the  energy 
generated  by  the  same  amount  of  hay 
consumed  by  horses.  But  to  l>r. 
Joule,  of  Manchester,  in  our  own  time 
is  due  the  first  great  onward  move- 
ment, in  the  discovery  and  determina- 
tion of  the  mechanical  equivalent  of 
heat.  Joule's  numerous  experiments 
on  the  exact  relation  between  heat 
and  mechanical  energy  resulted  in 
the  establishment  of  a  formula  of 
equivalence  in  terms  of  kilogiamme- 
tres  necessary  to  raise  by  one  degree 
centigrade  the  temperature  of  one 
kilogramme  of  water.  More  popu- 
larly put,  he  showed  that  the  energy 
required  to  raise  a  weight  of  one  lum 
dred  pounds  through  one  foot  was 
equivalent  to  the  amount  required  to 
raise  a  certain  fixed  quantity  of  water 
through  one  degree  in  temperature. 
Starting  from  this  settled  point,  it 
soon  became  clear  to  physical  think- 
ers that  every  species  of  energy  was 
more  or  less  readily  convertible  into 
every  other,  and  that  an  exact  luiiner- 
ical  equivalence  existed  between  them. 
This  principle,  which  first  clearly 
emerged  into  the  consciousness  of 
physicists  about  the  middle  decades  of 
the  present  century,  was  originally 
known  under  the   name  of  Persistence 


of  Force,  in  which  form  Grove's  well- 
known  little  treatise  helped  largely  to 
ties,  to  politics,  to  religion,  and  to !  popularize  its  acceptance.  liut  as 
human  activities  and  products  gener- !  time  went  on,  the  underlying  distinc- 
ally.  In  Spencer,  evolutionism  finds  s  tion  between  force  and  energv  came 
its  personal  avatar:  he  has  been  at  j  to  be  more  definitely  realized,  and 
once  its  prophet,  its  priest,  its  archi- '  the  phrase  conservation  of  eneigv  be- 
tect,  and  its  builder.  j  gan  to  supersede  the  older  and   erro- 

Second  only  in  importance  to  the  1  neous  terminology.  The  realization 
evolutionary  movement  among  the  ;  of  the  varying  nature  of  eneigv  as  po- 
scienlific  advances  of  our  own  day  |  tential  and  kinetic  helped  in  the  trans- 
must  be  reckoned  the  establishment '  formation  of  the  prime  concept.  /\t 
of  that  profound  fundamental  physi- '  last,  under  the  hands  of  Clausius, 
cal  principle,  the  conservation  of '  Helmholtz,  Mayer,  Clerk  Maxwell, 
energy.  Even  before  the  beginning '  Tait,  and  Balfour  Stewart,  the  doc- 
of  our  half  century,  Davy  and  Rum- '  trine  assumed  its  modern  form — that 
ford  (especially  the  latter)  had  caught  '  all  energies  are  mutually  convertil)le, 
faint   glimpses   of    the   coining  truth  ^  and  that  the  sum-lolal  of  energy,  po- 


40 


THE   PROGRESS   OF  SCIENCE  FROM    1 836  TO    1 886. 


teniial  and  kinetic,  is  a  constant  quan- 
tity throughout  the  cosmos. 

The  practical  applications  of  the 
doctrine  of  energy  are  as  yet  only  in 
their  infancy.  The  whole  mass  of 
theoretical  science  has  to  be  re-written 
in  accordance  with  this  new  and  fun- 
damental law.  The  whole  field  of 
applied  science  has  to  be  developed 
and  enlarged  by  the  light  of  this  preg- 
nane and  universal  principle.     Its  im- 


that  moment,  under  the  fostering  care 
of  Faraday,  Daniell,  Cooke,  Morse, 
Arago,  Tyndall,  Edison,  and  Thom- 
son, electric  science  became  a  power 
in  the  world.  The  whole  theory  of 
electricity  as  a  mode  of  energy  has 
since  been  fully  explored  and  ex- 
pounded. A  vast  field  has  been 
added  to  science.  Units  and  modes 
of  absolute  measurement  have  been 
invented.  The  telephone  and  micro- 
phone have  been  introduced  ;  sec- 
ondary batteries  have  been  formed 
and  improved  ;  the  dynamo  has  be- 
come a  common  object  of  the  country  ; 
and  the  electric  light  has  grown  under 
our  very  eyes  into  a  practical  and  ex- 
tremely dazzling  reality.     Electricity, 


plications  are  all-pervading.  In 
astronomy  it  has  profoundly  alTected 
all  our  conceptions  as  to  the  sun's 
heat,  the  orbits  of  planets,  the  nature 
of  meteors,  the  past,  present,  and  fu- 
ture of  the  universe.  In  biology  it 
has  taught  us  to  envisage   t"he   plant 

mainly  as  a  machine  in  which  kinetic !  as  we  know  it,  with  all  its  manifold 
energy  is  being  transformed  into  po-  useful  applications,  is  almost  entirely 
tential ;  the  animal  mainly  as  a  ma-  a  creation  of  the  last  half  century. 
chine  in  which  potential  energy  is  be-  In  physics  the  present  epoch, 
ing  transformed  back  again  into  though  chiefly  remarkable  for  the 
kinetic.  In  meclianics  and  the  me-  series  of  investigations  which  led  up 
chanical  arts  it  has  produced  and  is  to  the  discovery  of  tlie  law  of  conser- 
producing  immense  changes.  And  in  j  vation,  has  also  illustrated  many 
the  future  it  is  destined  still  more  j  minor  principles  of  the  first  im- 
profoundly  to  alter  our  ineclunical  |  portance.  The  true  theory  of  heat 
ideas  and  activities  :  the  great  revolu-  [  and  the  laws  of  radiant  energy  have 
tion  there  is  only  just  beginning ;  |  been  definitely  formulated.  The  un- 
another  half   century   is   yet  needed   dulatory  theory  ot   light — a  discovery 

of  the  previous  quarter  century — has 
been  universally  adopted  and  justified. 
Thermo-dynamics  have  been  elevated 


fully  to  develop  it 

These  two  great  principles — evolu- 
tion and  the  conservation  of  energy — 
form  the  main  bulk  of  our  age's  addi- 
tion to  the  world's  accunulated  stock 
of  knowledge.  But  among  the  sepa- 
rate sciences  many  wontlerful  ad- 
vances have  also    been    made   which 


into  a  great  and  increasing  branch  of 
science.  Sir  William  Thomson's  law 
of  dissipation  of  energy  has  completed 
and  rounded  off  the  tlieory  of  conser- 
vation.    The  causes  and   methods  of 


cannot  be  overlooked  in  the  briefest   glacier  motion  have  been  investigated 


retrospect  of  the  half  century's  gains 
To  these   a  few  words  must   next    be 
devoted. 

Amon<r    sciences  of    the   n!)stract- 


and  established.  I'liotography  has 
almost  passed  through  its  entire  life- 
cycle.  The  pol  •  "ation  of  light  has 
been  observed  and  studied.  Spectrum 
concrete  group  electricity  had  hardly  j  analysis  has  come  into  the  front  rank 
got  beyond  the  stage  of  an  elegant  I  as  an  instrument  of  research.  In 
amusement  at  the  opening  of  our  short,  a  greater  number  of  new  physi- 
epoch.     Statical    electricity  was  still    cal  phenomena  have   been  discovered 


the  department  about  which  most  was 
known.  Galvanism  as  y('t  stood  apart 
as  a  distinct  study.  Its  connection 
with  magnetism  had  not  long  been 
proved  by  the  discoveries  of  Oersted. 
In  1837  itself,  however,  Wheatstone 
constructed  the  first  telegraph.     From 


or  old  ones  interpreted  than  in  the 
whole  space  of  previous  time  put 
together. 

In  chemistry,  the  advance  has  been 
more  in  detail  than  elsewhere.  Chem- 
ical science  alone  still  remains  a 
somewhat  fragmentary  mass  of  indi- 


THE   PROGRESS  OF   SCIENCE   FROM    1 836  TO    1 886. 


41 


)een 
111  e  ni- 
ls a 
lindi- 


vidual  facts  and  observations,  colli- 
gated by  minor  laws  and  analogies, 
but  uniliuminated  as  yet  by  the  broad 
light  of  any  great  and  all-embracing 
general  principles.  Since  Dalton's 
atomic  theory,  indeed,  no  philosophic 
generalization  of  the  very  first  magni- 
tude has  been  introduced  into  chemis- 
try. But  generalizations  of  the  sec- 
ond order — vastly  interesting  to 
chemists,  and  to  chemists  alone — 
have  been  made  in  such  numbers  as 
to  defy  enumeration  ;  wider  concep- 
tions have  in  many  ways  sprung  up  ; 
the  science  has  assumed  a  new  form  ; 
and   some  of  the   results  of  spectrum 


ful.  The  invention  of  the  spectro- 
scope, and  the  rapid  development  of 
spectrum  analysis,  have  placed  in  the 
hands  of  astronomers  a  uiethod  and 
an  instrument  inferior  in  value  only 
to  the  telescope  itself.  It  is  not  so 
long  since  Comle  dogmatically  de- 
clared we  could  never  know  anything 
of  the  chemical  composition  of  the 
fixed  stars.  Scarcely  were  the  words 
well  out  of  his  mouth  when  the  in- 
vention of  the  spectrosco|)e  and  its 
application  to  the  spectra  of  incandes- 
cent bodies  brought  the  investigation 
of  the  elements  in  the  sun  ami  stars 
well  within  the  reach  of  human  possi- 


analysis  and  of  the  new  chemistry  j  bility.  'J'he  successive  res^-arches  of 
lead  to  the  hope  that  this  science  too  1  VVheatstone,  Foucaiilt,  Secchi,  Bun- 
is  on  the  eve  of  arriving  at  that  stage   sen,  KirchhufT,  and  Nnrman  Lockyer, 


of  far-reaching  fundamental  truths 
which  it  is  the  special  function  of  our 
generation  to  bring  about. 

Mathematics  have  also  undergone 
a  new  development,  scarcely  capable 
of  being  rendered  comprehensible  to 
the  lay  intelligence. 

The  applications  of  physical,  elec- 
trical, and  chemical  science  in  the 
great  mechanical    and   industrial    in- 


exactly covering  our  fifty  years,  have 
at  last  enabled  us  to  prove  almost 
with  certainty  the  presence  in  the 
solar  envelopes  of  several  inetals 
already  known  in  the  earth's  crust, 
such  as  potassium,  sodium,  calcium, 
iron,  nickel,  and  chromium.  So  deli- 
cate is  the  spectroscopic  test  that  it 
renders  possible  the  detection  of  so 
small  a  fraction  as  the  two  hundied 
ventions  of  our  iron  age  belong  else-  i  millionth  part  of  a  grain  of  sodium, 
where,  and  are  already  familiar  in  '  And  by  revealing  bright  lines  in  the 
many  respects  to  all  of  us.  Railways  j  spectrum  not  previously  referable  to 
slightly  antedate  the  epoch  ;  the  tele- 1  any  known  body,  it  has  been  the 
graph  is  just  coeval  with  it.  'J"he  first  j  means  of  discovering  fiv^e  new  metals, 
submarine  cable  was  in  185 1,  the  first   cctsiuni    and    rubidium   (detected   by 


transatlantic  in  1866.  Electro-plating, 
the  steam-hammer,  the  Armstrong 
gun,  the  Bessemer  process,  must  not 
be  forgotten.     Other  triumphs  of   ap- 


Bunsen),  thallium  (by  Crookes),  in- 
dium (by  Richter),  and  gallium  (by 
Lecoq). 

Our  knowled<re  of  the  sun's  consti- 


plied    science    fall   more   fitly   under ,  tution,    in    particular,    has    advanced 

another  heailing.  with  extraordinary  rapidity  during  the 

Among      the     concrete      sciences,    period     here     nnder     review.     Even 

thirty  years  ago  we  knew  little  of  the 
central  orb  of  our  svstem  save  a  few 
naked  mathematical  facts  as  to  his 
diameter,  his  density,  his  attractive 
power,  and  the  spots  on  his  surface. 
Thirty  years  of  constant  investigation 
have  now  enabled  us  to  picture  to  our- 
selves with  tolerable  accuracy  the  ac- 
tual state  of  the  sun's  fiery  exterior. 
The  new  era  began  with  Schwabe's 
discovery  of  the  periodicity  of  the 
sun's  spots  in  185 1.  The  develop- 
ment   of   spectroscopic   analysis   be- 


astronomy  has  made  vast  advances 
during  the  past  half  century.  Lord 
Rosse's  great  telescope  was  set  up  ai 
Parsontown  in  1844.  Two  years 
later,  Leverrier  and  Adams  made 
their  curious  simultaneous  discovery 
of  the  planet  Neptune.  But  it  is  not 
so  much  in  new  lists  of  suns  or  satel- 
lites— though  the  name  of  these  alone 
has,  indeed,  been  legion — as  in  the 
fresh  light  cast  upon  the  nature  and 
constitution  of  olc^r  ones,  that  our 
age  has  been  most  singularly  success- 


'IL, 


42 


THE   PROGRESS  OF  SCIENCE   FROM    1 836  TO    1 886. 


tween  1854  and  1870  followed  hard 
on  this  first  impulse.  Since  i860 
eclipses  have  yielded  us  valuable  re- 
sults. Observations  on  transits  of 
Venus  have  largely  corrected  a  seri- 
ous error  in  our  calculations  of  our 
primary's  distance  from  the  earth. 
Janssen  and  Lockyer  have  taught  us 
how  to  observe  at  any  time,  by  means 
of  the  spectroscope,  phenomena  which 
were  previously  observable  only  dur- 
ing moments  of  total  eclipse.  Hug- 
gins  has  shown  us  how  to  isolate  those 
marvelous  protuberances  of  incandes- 
cent gas  which  burst  forth  with  explo- 
sive violence  from  tmie  to  time  from 
the  edge  of  the  photosphere.  Tacchi- 
ni,  Secchi,  Young,  and  others,  have 
carried  out  these  interesting  research- 
es to  a  still  higher  pitch  of  certainty 
and  accuracy  ;  and  the  sun's  geogra- 
phy, so  to  Si^eak,  is  to-day  no  longer 
a  closed  book  to  mundane  observers. 
We  know  our  central  luminary  now 
as  a  mass  of  intensely  heated  gas, 
surrounded  by  a  shell  of  luminous 
cloud,  the  photosphere,  formed  by  tlie 
cooling  of  condensable  vapors  at  the 
surface  where  exposed  to  the  cold  of 
outef  space  ;  and  floating  in  a  chromo- 
sphere of  incondensable  gases  (nota- 
blv  hvdrojjen)  left  behind  bv  the  for- 
niation  of  the  photospheric  clouds. 
The  mysterious  corona  alone  as  yet 
evades  our  methods  of  research. 

In  the  solar  system  at  large,  great 
advances  have  been  made  in  the  de- 
tails of  planetary  astronomy.  The 
differences  in  kind  between  the  older 
group  of  interior  planets,  now  in  their 
cold  and  solid  age,  and  the  younger 
group  of  exterior  planets,  still  in  their 
boisterous  and  fiery  youth,  has  been 
well  ascertained.  ThI;-,  truth — of  so 
much  interest  from  the  evolutionary 
point  of  view — has  b'>en  especially 
worked  out  by  R.  A.  Proctor.  Nas- 
mytli's  observations  on  our  own  dead 
satellite,  the  moon,  have  given  us  a 
graphic  and  appalling  picture  of  a 
worn-out  world  in  its  last  stage  of  life- 
less, waterless,  and  airless  decrepi- 
tude. New  moons  have  been  added 
to  Mars,  and  several  tedious  ndditions 
have  been  made  by  minutely  obstet- 


rical astronomers  to  the  already  in- 
conveniently large  family  of  the  minor 
planets.  AH  our  fresh  knowledge  of 
Jupiter  and  Saturn,  those  tinbulent 
and  volcanic  orbs,  has  helped  to  im- 
press the  general  soundness  of  the 
evolutionary  hypothesis  ;  while  the  in- 
creasingly important  study  of  meteors 
and  comets  has  brought  us  close  to  the 
very  threshold  of  the  great  ultimate 
mystery  of  star-genesis  and  world- 
forming.  The  extreme  tenuity  of  the 
mass  of  comets,  the  inconceivable 
rarity  of  the  matter  composing  their 
gaseous  tails,  the  ci  rious  phenomena 
of  their  instantant  ous  reversal  on 
passing  their  peri  lelion,  the  proof 
that  their  light  is  partly  reflected  and 
partly  direct,  the  s^Dectroscopic  deter- 
mination of  their  composition,  the 
discovery  of  the  essentially  planetary 
nature  of  meteor-streams,  and  the  rec- 
ognition of  their  vast  numbers  swarm- 
ing through  space,  are  among  the  most 
striking  novelties  of  the  last  half  cent- 
ury in  this  direction. 

In  sidereal  astronomy,  besides  the 
mere  mechanical  increase  of  mapping, 
the  chief  advances  have  been  made 
in  observations  upon  double  stars, 
spectroscopic  analysis  of  fixed  stars 
and  of  nebiilai,  and  consecjuent  proof 
of  the  fact  that  truly  i  Tesolvable  neb- 
ulfE  do  really  exist,  the  gaseous  raw 
material  of  future  stars  and  solar  sys- 
tems. It  must  be  added  that  within 
the  half  century  the  hypothetical  ether 
has  amply  vindicated  its  novel  claim 
to  take  its  place  as  a  mysterious  entity 
side  by  side  with  matter  and  energy 
among  the  ultimate  components  of 
the  objective  universe. 

In  geology  the  chief  theoretical  ad- 
vances have  been  made  by  the  recog- 
nition of  the  cosmical  aspects  of  the 
earth's  history  ;  its  relations  to  nebula, 
sun,  and  meteor ;  the  importance  of 
eccentricity  and  precession  of  the 
equinoxes,  and  the  possible  results  of 
ancient  changes  in  its  rates  of  motion, 
tides,  and  so  forth.  Dynamical  geol- 
ogy has  made  vast  strides,  especially 
in  the  investigation  of    volcanic    phe- 


nnmena.  mountain 


•bu 


ilflni":,    an 


d    tl 


le 


birth  and  growth  of  i:ilands  and  con- 


THE  PROGRESS  OF  SCIENCfi  FROM    1 836  TO    1886. 


43 


lars, 
Slavs 
roof 
neb- 
raw 
sys- 
^ith'.n 
ether 
claim 
nitity 
lergy 
ts   of 

il  ad- 
-cog- 
the 
"Ibula, 
le    of 
the 
Its  of 
]lion, 
ifenl- 
lially 
jplie- 
the 
I  con- 


tinents. The  science  of  earth-sculp- 
ture has  been  developed  from  the 
very  beginning.  Straligraphical  geol- 
ogy has  been  largely  improved.  And 
in  palreontology  an  immense  number 
of  the  most  striking  and  interesting 
of  fossil  forms  have  been  brought  to 
light.  Among  them  may  be  specially 
mentioned  those  which  have  proved 
of  critical  importance  as  evidences  of 
the  truth  of  organic  evolution — the 
toothed  birds  of  the  Western  Ameri- 
can cretaceous  deposits,  the  lizard- 
like bird  or  bird-like  feathered  lizard 
of  the  Solenhofen  slates,  Marsh's  re- 
markable series  of  ancestral  horses, 
Cope's  beautiful  reconstruction  of  the 
fossil  progenitors  of  existing  camels. 
Monkeys  certainly,  anthropoid  apes 
clearly,  man  dnuijtfully,  have  been  de- 
tectecl  in  the  fossil  state.  India,  Aus- 
tralia, Canada,  tiie  United  Slates  have 
been  explored  and  surveyed,  geologi- 
cally and  palaiontologically ;  and  the 
exploitation  of  the  far  West  in  partic- 
ular has  not  only  added  immensely  to 
our  knowledge  of  life  in  past  times, 
but  lias  also  revolutionized  our  con- 
ceptions as  to  die  gradual  growth  and 
devL''opine!it  of  continental  areas,  and 
the  occasional  vast  sjale  of  volcanic 
phenomena.  Tiie  permanence  of  all 
great  continents  and  oceans  is  now  a 
proved  truth  of  geolo-4,y.  It  has  been 
reinforced  and  extended  from  a  totally 
ditYvrent  point  of  view  by  Alfred  Rus- 
sel  Wallace,  whose  masterly  works  on 
the  Gi.'Oi; rap  Ideal  Distribution  nf  Ani- 
mals and  on  Is/an  I  Lift:  have  immense 
geological  as  well  as  biological  iinpli- 
cati'jus. 

In  pure  biology,  besides  the  grand 
advance  implied  in  the  establishment 
of  the  doctrine  of  descent  with  modi- 
fication, and  its  subsidiary  principles 
of  survival  of  the  fittest  and  sexual 
selection,  profotmdly  important  minor 
results  have  also  been  attained  in 
many  directions.  Embryology  in  the 
hands  of  Von  Baer  and  his  success- 
ors, notably  Kowalevsky  and  Balfour, 
has  acquired  prime  importance  as  an 
instrument  of  geological  research. 
(^onin;)r  itive  osteoloi^jv  in  the  hands 
of  Owen,  Iluxley,  Gaudry,  and  Busk, 


has  given  us  new  Views  6f  the  rela- 
tionships between  vertebrate  animals. 
The    pedigree   of  fishes,  anipliil)ians, 
reptiles,  birds,  and  mammals,  has  been 
worked   out  with  a  considerable    de- 
gree of  fulness  from   the  hints  suj> 
plied  us  by  the  amphioxus,  the  ascid- 
ian    larva,  the    facts   of   embryology, 
and  the  numerous  recent  discoveries 
of  intermediate  or  arrested  organisms, 
recent     and     extinct.       Invertebrate 
zoology  has  been  rescued  from  chaos 
and  partially  reduced   to   temporary 
and    uncertain    order.      Botany,    at 
once  the  dullest  and  the  most  alluring 
of   all    sciences,  has  been    redeemed 
from  the  vicious  circle  of  mere  classi- 
ficatory  schemes,  and  vivified  by  the 
fresh   and  quickening  breath  of  the 
evolutionary   spirit.     The    new   mor- 
phology has  revolutionized  our  ideas 
of  vegetal  homologies  ;  the  new  phy- 
siology has  fastened  all  its  attention 
on  the  adaptations  of  the  plant  to  its 
natural  environment.    The  fascinating 
study  of  tht  mutual  relations  between 
flower  and   nsect  in  particular,  set  on 
foot  before  the  dawn  of  our  epoch  by 
Christian  Sprengel,  but  re-introduced 
to  notice  in  recent  times  by  Darwin's 
works  on    orchids  and  on   cross  fertil- 
ization, has  been  followed  out  with  ar- 
dor  to    marvelous     results   by    Her- 
mann  Miiller,  Axel,    Delpino,   Hilde- 
brand,    Lubbock,    Ogle     and    others. 
Heer  and  Saporia  have  worked  out  in 
great  detail  the  development  of  sev- 
eral  fossil   floras.     Last  of  all,  Her- 
bert Spencer  has  cast  the  dry  light  of 
his  great  organizing  and  generalizing 
intelligence  on   the   problems   of  he- 
redity, genesis,  variation,  individuality, 
j  and  the  laws  of  multiplication.     Fifty 
years  ago  biology  was  a  mighty  maze 
I  wholly  without    a  plan.     To-day   the 
I  clue   has   been  found   to  all  its  main 
avenues,  and    even    the    keys    of    its 
I  minor  recesses   are  for  the  most  part 
!  well  within  reach  of  the  enlightened 
j  observer. 

j  Even  the  actual  gains  in  the  num- 
i  ber  of  new  organisms  addeil  to  our 
!  lists  during  the  last  half  century  are 
in  tlitunselves  ast'inisliin;; ;  and, 
\  strange  to  say,  the  species  that  bear 


44 


THE   PROGRESS  OF  SCIENCE  FROM    1836  TO    1 886. 


it 


most  closely  upon  the  theory  of  or- 
ganic evolution  are  almost  all  of  them 
quite  recent  additions  to  our  stock  of 
knowledge.     The  gorilla  appeared  on 
the  scene  at  the  critical  moment  for 
the   Descent  of  Man,      Just   on   the  j 
stroke  vviicn   they  were  most   needed,  1 
connecting  links,  both  fossil  and  liv- 
ing,  turned  up  in  abundance  between 
fish  and  amphibians,  amphibians  and 
reptiles,     reptiles     and    birds,    birds 
and     mammals,    and    all     of     these 
together    in    a    perfect    network    of! 
curious   cross-relationships.      Lizards  • 
that   were    almost   crows,  nmrsupials 
that     were    almost    ostriches,    insec-  j 
tivores  that  were  almost  bats,  rodents 
that  were  almost  monkeys,  have  come  ' 
■ir  the  very  nick  of  time  to  prove  the  j 
i  I'lh   of   descent    with   modification. 
/^K-'ong    he  most   interestnig  of  these  j 
strn  ig';    coincidences  are    such  epi- 
sodes T.:-  the  vliscovery  in  the  rivers  of 
Queens! a;:''!  j^  that  strange  lung-bear- 
a\r  nnd    ;^)i!-L!e.ithing   fish,  the  bar- 
r.inuinda,  orly   •   s-\\\\   before  in   the 
fossil  form   as  a  long  extinct   species, 
but    m   whose   anatomical     structure 
Giinther   has  discerned   the    missing 
link  between  the  antique  ganoid  type 
of  fishes  on   the  one  hand,  and  the 
mudfish  and   salamandroid  amphibi- 
ans on  the  other. 

In  the  practical  applications  of  bio- 
logical and  physiological  science  to 
the  wants  and  diseases  of  human  life, 
two  at  least  deserve  mention  here.  An- 
aisthetics  are  almost  entirely  a  growth 
of  our  half  century  :  chloroform  was 
first  employed  in  operations  by  Simp- 
son in  1847,  '^"^  ^^^^  "^'^  ^f  other  simi- 
lar agents  is  still  more  recent.  Again, 
the  discoverv  that  zvmoiic  diseases  in 
men  and  animals  are  due  to  the  mul- 
tiplication within  the  body  of  very 
minute  organisms,  known  as  micro- 
bes, bacteria,  or  bacilli,  now  promises 
to  revolutionize  medical  science. 
Their  connection  with  decomposition 
was  still  earlier  detected.  The  names 
of  Pasteur,  Tyndall,  and  Koch  are 
specially  identified  with  researches 
into  the  nature  of  these  tiny  morbid 
organisms  and  the  best  means  of  pre- 


venting or  neutralizing  their  attacks, 
either  on  living  or  dead  matter. 

In  marvelous  contrast  to  the  frag- 
mentary and  disjunctive   science    of 
fifty  years  ago,  modern  science  at  the 
present  day  offers  us  the  spectacle  of 
a  simple,  unified,  and  comprehensible 
cosmos,  consisting  everywhere  of  the 
same  prime  elements,  drawn  together 
everywhere  by  the  same  great  foices, 
animated   everywhere    by    the    same 
constant  and  indestructible  energies, 
evolving  everywhere  along  the  same 
lines  ill  accordance  with  the  self-same 
underlying   principles.     It   shows  us 
the  community  of  ultimate  material  in 
sun   and   star,  in  nebula  and  meteor, 
in    earth    and    air    and   planet    and 
comet.     It  shows  us  identical  metals 
and  gases  in  fiery  photosphere  and  in 
electrically-heated  matter  in  our  own 
laboratories.     It  shows   us  atoms  of 
hydiogene   or   of     sodium    pulsating 
rhythmically     with    like    oscillations 
in      star-cloud     or      sun-cloud,     and 
in    London    or    Berlin.     It   exhibits 
to  our  eyes  or  to  our  scientific    im- 
agination a    picture    of  the    universe 
as  a  single  whole,  a  picture  of  its  evo- 
lution as  a  continuous  process.     One 
type    of   matter   diffused    throughout 
space ;    one      gravitative     attraction 
binding  it  together   firmly  in    all    its 
parts,  one  multiform  energy  quiver- 
ing through  its  molecules  or  travers- 
ing its  ether,   in   many  disguises   of 
light,  and  heat,  and  sound,  and  e'ec- 
tricity.     It  unfolds  for   us  in    vague 
hints   the   past  of  the  universe   as  a 
difTuse   mass  of  homogeneous  matter, 
rolling  in  upon  its  local  centers  by 
gravitative  force,  and   yielding  up  its 
primitive  energy  of  separation  as  light 
and  heat  to  the  ethereal  medium.     It 
suggests  to  us  this  primitive  energy  of 
separation   as  the  probable  source  of 
such  light  and  heat  in  suns  and  stars 
as  we  now  know  them.     It  posits  for 
us  our  own  planet  as  an  orb  gathered 
in  from  the  original  cloud-mass,  witii 
outer  surface  cooled  and  corrugated, 
and  with  two  great  envelopes,  atmos- 
pheric and  oceanic,  gaseous  and  liq- 


uid,    still    floating     or     precipitated 


THE   PROGRESS   OF  SCIENCE   FROM    1 836  TO    1886. 


45 


around  its  denser  core.  It  teaches 
us  how  the  hard  crust  of  the  hot  qeii 
tral  mass  has  been  uplifted  here  into 
elevated  table-land,  or  depressed 
there  into  hollow  ocean-bed.  By  the 
aid  of  its  newest  instrument,  meteor- 
ology, it  lets  us  see  how  incident  solar 
ciiL'r^ijy,  raising  clouds  and  causing 
rainfall,  with  its  attendant  phenomena 
of  drainage  and  rivers,  has  carved 
and  duiiuded  the  upheaved  masses 
into  infinite  variety  of  hill  and  valley. 
It  shows  us  how  sedimtiiit,  thus 
gathered  by  streams  on  the  bed  of 
the  sea,  is  pushed  up  once  more  by 
volcanic  power  or  lateral  pressure  in- 
to alpine  chains  and  massive  conti- 
nents, and  how  these  in  their  turn 
have  been  worn  down  by  the  long- 
continued  bombardment  of  aqueous 
or  aerial  action  into  mere  stumps  or 
relics  of  their  primitive  magnitude. 
It  puts  before  us  life  as  an  ultimate 
result  of  solar  energy  falling  on  the 
watery  and  gaseous  shell  of  such  a 
solidified  planet.  It  suggests  to  us 
how  light,  acting  chemically  on  the 
leaves  or  fronds  or  cells  of  the  green 
herb,  stores  up  in  them  carbohy- 
drates, rich  in  potential  energy,  which 
animals  afterwards  use  up  as  food,  or 
man  utilizes  as  coal  in  his  grates  and 
his  locomotives.  It  exhibits  to  us  the 
animal  organism  as  essentially  a  food- 
engine  in  whose  recesses  solar  energy, 


stored  as  potential  by  the  plant,  is 
once  more  let  loose  by  slow  combn.s- 
tion  in  the  kinetic  form  as  heat  and 
motion.  It  enables  us  to  regard  the 
body  as  a  machine  in  which  stomach 
and  lungs  stand  for  furnace  and 
boiler,  the  muscles  for  cylinder,  pis- 
ton, and  wheels,  and  the  nervous  sys- 
tem for  an  automatic  valve-gtar.  It 
traces  for  us  from  small  beginnings 
the  gradual  growth  of  limb  and  organ, 
of  flower,  fruit,  and  seed,  of  st-nse 
and  ijitellect.  With  the  simj)le  key 
of  survival  of  the  fittest  it  unlocks 
for  us  the  secret  of  organic  diversity 
and  universal  adaptation.  It  recon- 
structs for  us  from  obscure  half-hints 
the  origin  of  man  ;  the  earliest  stages 
of  human  history ;  the  rise  of  speech, 
of  arts,  of  societies,  of  religion.  It 
unifies  and  organizes  all  our  concepts 
of  the  whole  consistent  system  of 
nature,  and  sets  before  our  eyes  the 
comprehensive  and  glorious  idea  of  a 
cosmos  which  is  one  and  the  same 
throughout,  in  sun  and  star  and  world 
and  atom,  in  light  and  heat  and  life 
and  mechanism,  in  herb  and  tree  and 
man  and  animal,  in  body,  soul,  and 
spirit,  mind  and  matter.  Almost  all 
that  is  most  vital  and  essential  in 
this  conception  of  our  illimitable 
dwelling-place,  the  last  half  century 
has  built  up  for  us  unaided. 


CONTENTS. 


PACB 


I.  The  Advance  of  Science  in  the  Last  Hatt-century. 
II.  The  Progress  of  Science  from  1836  to  t886 


33 


THE 

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A  CATALOGUE  RAISONNE. 

Containing  all  the  Works  in  the  Humboldt  Library 

(up  to  and  including  No.  96),  grroupecl  according: 

to  their  i^^Ubject-lliatter,  for  the  convenience  of 
those  who  desire  to  becomt*  familiar  with  tlie  results  of 
scientific  inquiry  in  any  of  the  following  departments : 


I.  EVOLUTION.     Nos.  10,  30,  40,  58.  oO,  94  ;   23  (criticism)  sec 
also  Nos.  17,  21,  73. 

II.  MAN  :  OHIO  IN;  PLACE  IN  NATURE.    No^  4,  71,  74,  7"),  70,  77. 

III.  EARLY  HISTORY  OF  MAN.     Kos.  25,  44,  45,  GO. 

IV.  RELIGION;   MYTlIOLOCiY.     Nos.  35,  47,  54,  02,  09,  81.     See 

also  Nos.  08,  90. 

V.  ETHICS;  MANNERS   AND   CUSTOMS.     Nos.  9,  28,  55,  03. 
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VI.  PSYCHOLOGY.     Nos.  13,  22,  40,  52,  50,  57.     Sec  also  Nos.  32, 
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VII.  EDUCATION ;    LANGUAGE.     Nos.  5,  8,  30,  31,  34,  91.     See 
also  Nos.  21,  53,  01,  00,  73. 

VIIL  POLITICAL  AND  ECONOMIC  SCIENCE.     Nos.  3,  27,  42,  50, 

61,  78,  83.     See  also  Nos.  08,  70,  90. 

IX.  BIOGRAPHY ;  HISTORY  OF  SCIENCE.     Nos.  43,  80,  89,  90. 

X.  MEDICINE;  EPIDEMICS.     Nos.  15,  07,  72,  87. 

XI.  ASTRONOMY.     Nos.  14,  20,  49.     Sec  also  Nos.  1,  19,  24,  41, 
82,  90. 

XII.  GEOLOGY.    Nos.  0,  38,  39.     See  also  Nos.'  21,  41,  79. 

XIII.  PHYSICS.     Nos.  2,  7,  10,  18,  37. 

XIV.  BIOLOGY  ;  ZOOLOGY  ;  BOTANY.     Nos.  11,  12,  20,  29,  33,  48, 
04,  84,  92.  ' 

XV.  MISCELLANEOUS.     Nos.  1,  17,  19,  21,  41,  53,  01,  G6,  08,  70, 
73,  79,  82,  80,  90. 


CATALOGUE  OF  THE 


4,  41, 


53,  48, 
8,  70, 


HUMBOLDT   LIBRARY. 

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J.    FITZGERALD,    PVBLlSnER, 

24  East  Fourth  Street. 


No.    1.     lilsht     Sricnre     Tor     I.clMiire 
lloum  :  A  siTics  (if  Kiimiliar  Kssays  on  Scrcii- 
tilic  Sul)jc(ns.    Hy  Rii  mauu  A.  I'mn  lou,  K.R.A.S. 
Contents  (in  part) :— Tlic  Karth  a   Magnet  ;  the 
Secret  of  the  North    Hole;  Our  Chief  Timepiece 
I.osinfj  Time;  Tornadoes;  Influence  of  Marriage 
on  the  Death  Rale  ;  Squarln^;  thi'  Circle  •  the  Use- 
fulness of    Earthquakes ;  the  Forcing  Powor   of 
Rain,  etc.,  etc. 

No.  3.  The  ForiiiM  of  Water  in  Clouds  and 
Rivers,  Ice  and  (ilaciers.  By  John  Tv.nij.\ll, 
I.I..D.,  F.R.S.  ulluslrat(td). 

Contents  (in  part)  :— Oceanic  Distillation  ;  Archi- 
tecture of  Snow  ;  The  Motion  of  Glaciers;  Icicles; 
ICrratic  Blocks;  Tropical  Rains;  Atomic  Holes; 
1-iirthof  a  Crevasse  ;  Moraine  Ridjjes,  etc.,  etc.,  etc. 

No.  3.  PliyNi<-N  and  PollticH:  -An  Appli- 
cation of  the  I'liucijiks  of  Natural  Selection  and 
Jlcredityto  Political  Society.  By  VV.m.tkk  Bai;k- 
HOT,  Author  of  "  The  English  Constitution," 
etc. 
Contents; — The  Preliminary   Age ;  the  Use   of 

Conflict ;  Nation  Making  ;  the  Age  of  Discussion  ; 

Veritiable  Progress  Politically  Considered. 

No.  1.  Kvldciieo  aN  to  niuii'MPIaro  in 
Nature.  By  Thom.vs  Hu.\i.iiv,  F.R.S.  (,i"iJS- 
trated). 

Contents:— The  Natural  History  of  the  Manlike 
Apes;  The  Relations  of  Man  to  the  Lower  Ani- 
mals; Fossil  Remains  of  Man. 

No.  5.  KdiK'atlon  :  Intellectual,  ITIo^al 
and  Pliyctlcal.    By  Hi:iau:i<r  Siknckk. 
Contents  :— What  Knowledge  is  of  Most  Worth? 
Intellectual  Education  ;  Moral  Education  ;  Physi- 
cal Education. 

No.    6.     Town    Ocolos:|r.      By    the    Rev. 

CnARi.ES  KiNc.sLKV,  F.R.S.,  Canon  of  Chester. 

Contents :— The  Soil  of  the  Field  ;  the  Pebbles 
In  the  Street ;  the  Stones  in  the  Wall  ;  the  Coal  in 
the  Fire  ;  the  Lime  in  the  Mortar  ;  the  Slates  on 
the  Roof. 

No.  7.   The  Connervatlon  of  Encrgsr. 

By  Balfour  Stkwart,  F.R.S.  illustrated). 

Contents  ;— What  is  Energy  ?  Mechanical  En- 
ergy and  its  Change  into  Heat ;  The  Forces  and 
Energies  of  Nature ;  Transmutations  of  Energy  ; 
the  Dissipation  of  Energy;  the  Position  of  Life; 
Correlation  of  Nervous  and  Mental  Forces. 

No.  8.  fhe  Study  of  lianguages  brought 
back  to  its  true  Principles.     By  C.  Makcei.. 
Contents  :— Subdivision    and   Order  of    Study; 

the  Art  of  Reading;  the  Art  of  Hearing;  the  Art 

of  Speaking  ;  the  Art  of  Writing;  Mental  Culture  ; 

Routine. 

No.  0.  The  Data  of  Ethic*.    By  Herbert 

Spencer. 

Contents  ;— Conduct  in  General ;  Evolution  of 
Conduct ;  Good  and  Bad  Conduct ;  Ways  of  Judg- 


ing Conduct ;  The  Physical  View  ;  The  Rinlof^fical 
View  ;  the  Psychological  View  ;  the  Sociological 
View;  Criticisms  and  K.xplanations  ;  Relativity  of 
Pains  and  Pleasures;  Egoism  rs.  Altruism;  Al- 
truism 7'j.  Egoism;  Trial  and  Compri^mise:  Coa> 
ciliution  ;  Absolute  Ethics  and  Relative  Ltbica; 
the  Scope  of  Ethics. 

No.  10.  The  Theory  of  Sound  in  its  Rela- 
tion to  niUMlr.      By  PKOI  .  PlKlKO  Bl.ASI'.KNA,  ol 

the  Royal  University  of  Rome  (illustrated). 

Contents  (in  part) :-  Periodic  .Njovements,  vibra- 
tion ;  Transmission  of  Sound  ;  Characteristics  of 
Sound,  and  dilYerence  between  musical  sound  and 
noise;  Discords;  yu;dily  or  ti/n/'rf  of  musical 
sounds;  Italian  and  (ierni.m  music,  etc.,  etc. 

NoM.  11  and  I'i.  The  Nuturallitt  on  th« 
Hlvcr  AniuzoiiM:  -.\  Kecor^l  of  AiiventureiL 
H.ibits  of  Animals,  Sketches  of  Brazilian  ana 
Indian  Life,  and  Aspects  of  Nature  under  th« 
Equator,  during  eleven  years  of  Travel.  By 
Hk.vrv  VV'amer  Batks,  1''.R.S. 
*♦*  One  of  the  most  charming  books  of  travel  in 

our  language. 

No.  13.  mind  and  Body:  The  Theorienof 

their    Relation.     By   Ai.r  xa-.hkk    Bain,   LL.D., 

Professor  of  Logic   in   the  University  of  Aber» 

deen. 

Contents:— The  Ouostinn  Stated;  Conncctio*  of 
Mind  and  Body  ;  tVio  (.(miicrtion  viewed  a.s  corre.. 
spondence  or  concomitant  v^iri.uion  ;  (leneral  Laws 
of  Alliance  of  Mind  and  Body:  the  Feelings  and 
will  ;  the  Intellect  ;  How  are  Mind  and  Body 
United  ?     History  of  the  Theories  of  the  Soul. 

No.  14.  The  Wondcrw  of  the  Heavens. 

By  Camh.i.k  Fi.ammakion  (illustrated). 

Contents  (in  part):— The  Heavens;  the  Milky 
Way;  Double,  Multiple  and  Colored  Suns ;  the 
Planets ;  the  Earth  ;  Plurality  of  Inhabited  Worlds} 
Infinite  Space ;  Constellations;  TlieSun;  Comets; 
the  Moon,  etc.,  etc. 

No.  i't.  liOUgevlty:  the  Means  of  Prolong, 
ing  Life  after  the  Middle  Age.     By  John  Gjvkl>« 
NEK,  M.  D. 
Contents  (in  part) :— Is  the  Duration  of  Life  ia 

any  way  within  our  power?     Physiology  of  Ad>. 

vanced  Age  ;  Heredity  ;  Established  Facts  regard'. 

ing  Longevity,  etc.,  etc. 

No.  16.  On  the  Origin  of  Species;  or  the 

Causes  of  the  Phenomena  of  Organic  Nature:  A 

Course  of  Six  Lectures.     By  Thomas  H.  Hox- 

i.EY,  F.R.S. 

Contents :— Present  Condition  of  Organic  Nature; 
Past  Condition  of  Organic  Nature;  Origination  of 
Organic  Beings  ;  Perpetuation  of  Living  Beings; 
Conditions  of  Existence  ;  A  Critical  Examination 
of  Mr.  Darwin's  Great  Work, 

No.  17.  Progress :  Its  liair  and  Cause} 

with  other  disquisitions.    By  Hbruukt  SfSNCWU 


Co:iteBM:-  Vrnmretn;  the  Phtilo'ojnr  of  L»ii(jh- 
ter;  OrJKin  and  hunctlonH  of  Nfuaic  ;  tlie  Devvloii- 
ncnt  II)p(itiiL->i< ,  liiu  :jLi(.i.4l  (Ji'K^niiiiu }  the  L'sc 
of  AnthropomnrphiHin, 

•o.    18.    LttMoiiM    In    Elcrtrlcltjr.     By 

J»HM  TVNDAl.l.,  K.k.S.  (lllUHtralC(l). 

Contents  un  pitrtj:  The  Art  of  Kxperiincnt  ; 
Khnrtric  Induction;  l.khtinliirn'ii  Kiuurcs ;  Klic- 
Uica  «nd  Non-Electrics;  the  I.cydcn  Jar  ;  I'liysio- 
l«((icat  kflcct  of  the  r.lcctric  UiicharKU ;  Atmoii- 
phcrlc  Rleetricity,  rtc,  c-tc. 

No.  10.  Fain  1 1  III  r  ICNaayn  on  Srlouiiflc 
Hnkjet'tli.  ily  Ki'  hmh.  a.  I>i«u  r(.K,  I'.K.A.S. 
C!olitcMU!»  :~-()xyKi.n  in  llie  Sun  ;  Sun  spot,  Slurm 
■nd  Kamini- ;  New  wuyn  of  McviHurint;  the  Sun's 
l)iHtan«e:  Driftinc  I.ittht-wavcs  ;  The  new  Star 
which  faded  into  Star-mist  ;  Star-Kroupin^. 

No.  ao.  Tlio  Honiuneo  of  Aatrouomy. 

Hy  R.  Kaii>v  Mm  rh,  M.A. 

Contents:  — The  I'laiirts  ;  AstroloKv  ;  The  Moon  ; 
the  Sun  ;  the  Comets  :  I.aolace's  Nebular  ilypcjth- 
c«i»  ;  the  Stars;  the  Ncbulx- ;  Appendix. 
No.  ai.  On  tlip  PliyMloal  UamlM  of  Mi'o. 


Hasis  of  Life ;  Scientflic 
A  I'iecc  of  Chalk  ;  (ieoloj;- 
;  A   Liberal  EJucation  and 


With    other 

I.BV,  K.R.S 

Contents  ;  — Physical 
Aitiects  of  Positivism  ; 
icai  Contemporaneity 
where  to  find  it. 

No.  3!I.  MeclnK  and  Tliinklnff.    fiy  I'mf. 

Wii.i.iAM  KiMMiiiN  Ci.ii  I  cH.ii,  I'.K.S.  lillusiratcd). 

Contents;— The  Kye  and  the  Itrain  ;  the  Kye  and 
SeeinK  ;  the  Urain  and  Thinking;  On  Houndaries 
in  General. 
No.  its.  Srlentlllr  NoplilMnm  t  -A  Review 

of  Current    'I'heories  t<mceinin>,'   Atoms,  Apes 

and  Men.     Hy  Swii  m.  Wainkk.mi-,  l).\). 

Contents:— 'I  he  RiKln  of  Search  ;  Evolution;  A 
Puerile  Hypothesis  ;  Scientific  Levity  ;  a  House  of 
Cards;  Sophisms;  Protoplasm;  the  Three  Heifin- 
ninffs;  the  Three  Harriers;  Atoms;  Apes;  Men; 
Annna  Mundi. 

No.  34.  Popular    Sc'Icntlflo    Lectures. 

By  Prof.  U.  fliii.Miioi  1  /  (illiis:raled). 

Contents;— Tlie  Relation  of  Optics  to  I'aintlni,'. 
I.  Form.  a.  Shade.  ,\.  Color.  4.  Harmony  of 
Color  ;  the  Origin  of  the  Planetary  System  ; 
Thought  in  Medicine  ;  Academic  Freedom  in  Ger- 
man Universities. 

No.  as.  Tlio  Origin  ot°  Natlonw  1— Com- 
prisinif    two    diviKiuiis,   viz.:  — "  ICarly   Civiliza- 
tions,    and    "  lulinic    Altinities."      Hy   (Ikhki.k 
Rawi.in.son.  M.A.,  Camden  Professor  of  Ancient 
History  in  Oxford  I'niversity,  I^nf^land. 
Contents  :— Early  Civilizations  :  — Inlrndiiction  ; 
Antiquityof  Civilization  in  EnRland  ;  Antiquity  of 
Civilization  at  Habylon  ;  Phienician  Civilization  ; 
Civilizationsof  Phrvfjia,  Lydia,  the  Troas,  Assyria, 
Media,  India,  etc.;  Civilization  of' he  Hritisli  Celts; 
Civilization  of  the  Etruscans;  Pi-sults  of  .the  In- 
quiry.    Ethnic  Atlinitics  ;— Cliief  Jaiihctic  Races  ; 
Subdivisions  of  the  Japlietic  Races;  Chief  Hametic 
Races;  Subdivisions  of  Ciish  ;  Suhd  i  visions  of  Miz- 
raim  and   Canaan  :  the  Semitic  Races  ;  Subdivis- 
ions of  the  Semitic  Races. 

No.  26.  Tlio  Evolutionist  at  Large.    By 

Grant  Ai.i.kn. 

Contents  (in  part) :— Microscopic  Brains  ;  Slups 
and  Snails ;  Butterfly  Psycholof;y  •  In  Summer 
Fields;  Speckled  Trout;  Origin  of  VValnuts  ;  Do(,'S 
and  Masters,  etc.,  etc. 

No.  27.  The  History  of  Landlioldlng 
In  England.  Hy  Josici  11  Kisiiku,  F.R.H.S. 
Contents  un  part) :— The  Aborijiincs  ;  the  Scan- 
dinavians ;  the  Plantagenets  ;  the  Stuarts ;  the  Ro- 
mans ;  the  Normans ;  the  Tudors  ;  the  House  of 
llrunswick  ;  Land  and  Labor,  etc.,  etc. 

No.  28.  Fashion  In  Deformity,  as  Illus- 
trated in  the  Customs  of  Barbarous  and  Civil- 
wed  Races.     By  VVii.i.iam  Hknkv  Flowkh,  F.R.S. 
(illustratedV     To  which   is  added  :— manners 
and  Fashion.    By  Hkrukkt  Si'en(  ek. 
Contents  (in  part) :— Fashions  in  Coiffure;  Tat- 
tooing :  Deforming    the    Teetli  ;  Deforming    the 
Feet;  Eradicating  the  Eyebrows;  Ornaments  for 
the    Nose,  Ears,    Lips ;  Compressing  the  Skull ; 
BAects  of  Tight  Lacing,  etc.,  etc. 


No.  80.  Paets  and  FIrttens  orxooiogy. 

Hy  Andkbw  \Vii'.nN,  PJi.l),  (illuhlruleil). 

CimfiitH;  /o.  ;  i^ii.d  .'I'.lh'  ;  'lie  .Si  a  Serpnit» 
of  Science  :  Some  Animal  Architect*  ;  I'.ii'aHilrit 
and  Their  Uevclopmcnt  ;  What  I  iiaw  in  an  Aiu'h 
Nest. 

No*.  30  and  31.  On  tl:e  Ntudy  of 
Words.  By  Ri(  iiAni)Ciii.NKw\  Thk.n(  n,  D.I). 
(,'untents :  — Introduction  :  the  Poetry  in  Words; 

the    Morality  in   Words;  the    History  in  Wnrd^ ; 

the  Rise  of  New  Words  ;  the  Distinction  of  Words  ; 

the  Schoolmaster's  use  of  Words. 

No.    3*1.   Hereditary    Traits,    and    other 
Ivssuys.     Hy  K't  iiakd  A.  Pmn  ion,  |''.k,A.S. 
Contents  :-  Hereditary   Traits;   Arlilii  iai   Som- 
nambulism ;  Bodily  Illness  as  u  Mental  Stimulant ; 
Dual  Consciousness. 

No.    33.  VlKuettes    l>oni    Nature.     Hy 

(iKASI   All  KN. 

Contents  (in  part) :— Fallow  Deer;  the  Heron's 
Haunt;  Wild  Thynu- ;  the  Fall  of  the  Leaf;  the 
Hedgehog's  Hole;  Seaside  Wccils;  llic  Donkey'i 
Ancestors. 


Essays.       Hy     Thomas    II,    lUx- 


nophy  ol'  Ktyle.     Bv 

10  winch  Is  added  :-  TIlO 
.uo.     Hy    Ai.KXANOKK     Uain, 


No.  37.  Six  Lr 

TsNiiAi.i.,  F.R 

Contents:  —  Ir 

Theories;    Rela 


No.  3  1.  The 

Hhumi'ki  Si'im 
ITIothor    Tot. 

l.L.D. 

Contents  ;~Tlie  Principle  of  Economy  applied 
to  words-  Effect  of  I'iguralivc  Language  Ivx- 
plained;  Arrangement  of  Minor  Images  in  build- 
ing up  a  thought ;  The  Superiority  of  Poeiry  t<i 
Prose  explained  ;  Causes  of  Force  in  Language 
winch  depend  upon  I-'coiiomy  of  the  Mental  Sensi- 
bilities ;  the  Mother  Tongue. 

No.  3.>.  Oriental  Uelluions.  Edited  by 
Rev.  John  Caiuh,  D.D.,  I'resideiit  of  the  Uni- 
versity of  (jlasgovv. 

Contents :— Bralimanism  ;  Buddhism;  Confu- 
cianism ;  Zoroaster  an<l  the  /end  A  vesta. 

No.  30.  Leeturen  on  Evoliilioii,  with  a^^ 

Appendix   on   the   Ntlldy    ol'  HI«»lo|{y,     Hy 

TiioMAs  H.  Ilrxi.i-v,  K.K  S.  (illustrated). 

Contents:— The  Three  Hypotheses  respecting 
the  Ilistorvof  Nature;  the  I'lyiiotliesis  of  Evolu- 
tion—the Neutral  and  Favorable  I'Aidence  ;  \lie 
Demonstrative  Evidence  of  Evolution;  the  Study 
of  Biology. 

res  on  Light.     By  John 
stratedt. 

ory ;  Origin  of  Physic.il 
Theories  to  Experience  , 
Chromatic  Phenom,..ui  produced  by  Crystals; 
Range  of  Vision  and  Range  of  Radiation  ;  Sj)cc- 
trum  Analysis. 

Non.  38  and  30.  t.eologleal  Sketches 
at  Home  an«l  AbroatI ;  in  tuu  Parts,  each 
complete  in  itself.  By  Akchiiiai.u  Gicikik, 
F.R.S. 

Contents  :  Part  I ; — My  first  Geological  Excur- 
sion ;  "  The  Old  Man  of  Hoy  "  ;  the  Baron's  Stone 
of  Killochan  ;  the  Colliers  of  Carrick  ;  Among  the 
Volcanoes  of  Central  France  ;  the  Old  Glaciers  of 
Norway  and  Scotland ;  Rock-Weathering  meas- 
ured by  Decay  of  Tombstones.  Part  H;  A  Frag- 
ment of  Primeval  Europe  ;  In  Wyoming ;  The 
Geysers  of  the  Yellowstone  ;  the  Lava  lields  of 
Northwestern  Europe  ;  the  Scottish  School  of 
Geology  ;  (jcographical  Evolution  ;  the  Geologi- 
cal influences  which  have  affected  the  course  of 
British  History. 

No.  -10.  The  Selentlfle  EvIdeuee  of  Or- 
ganic Evolution.  Hy  Gi^okue  J.  Romanes, 
r .  R .  S . 

Contents  (in  part): — The  Argument  from  Classi- 
fication— from  Morphology  or  Structure — from 
Geology — from  Geographical  Distribution— from 
Embryology,  etc.,  etc. 

No.  41.  Current  Discussions  in  Sci- 
ence. By  W.  M.  Wii.i.iAMS,  F.C.S. 
Contents  (in  part):  The  Fuel  of  the  Sun;  Ori- 
gin of  Lunar  Volcanoes ;  Aerial  E.xj)loration  of 
the  Arctic  Regions ;  The  Air  of  Stove-heated 
Rooms,  etc.,  etc. 

No.  42.  History  of  the  Science  of  Poll- 
tics.      By  FUEDEKICK  Pol.l.oCK. 

Contents:  The  Place  of  Politics  In  Human 
Knowledge  ;  The  Classic  Period — Pericles— Soc- 
rates—Plato— Aristotle,  etc.;  the  Medieval  Period 


W, 

Co 
111. 
I'l 


F-xcur- 

,  Siiinc 

hllff  thl! 

tiers  ul 
ineas- 
Frap- 

■  ;   'I"'"-" 
l-lds  of 

lool  <;( 
poio^'i- 
Mse  of 

If  Or- 

Imanks, 

:iassi- 
-from 
-from 

Sci- 

;  Ori- 
lion  of 
lieatcd 

»oll- 

Juman 
(-Soc- 
Veriod 


—the  pBtmcy  %nA  the  Pmpire  ;  Rri;lnn!n(f  nf  the 
Moilern   IVrioil     Maclii.ivilli     Moblich ;  the   Mml 
cm  I'erioil  — I.otWi-    Honker     Ml  »  Kit  mc  — Hume— 
McirUfsijiiuu     IliirKc  ;  the  I'ri -.cut  I  ciiiurv     lUri- 
thaiii     Austin     Kuiil— S.ivit,'iiy ■  Hirhril  S|iiiiirr. 

No.  I'd.  OHru-lii  mid  lluniliuldt.  Ihfir 
lilves  mid  Work*!  (  oiuams  a  srms  ut 
n  lilies  (if  liarwln,  liy  lluxloy,  Koinuiu's,  (•cikio, 
Thisflton  Dyer  ;  aU»  tlir  lalo  I'rof.  AK.tssix'n 
Ontennial  Addrrsn  on  the  Lite  uiul  Work  nl 
Ale.xamltT  von  IIuinl)oldt. 

Noit.  41  mid  45.  The  Da«vii  oflllMtory  i 

an  iiuinduiiioii  to  l'rc-lli->t<iru   Sliuiy.     I'.diuil 

tiy  ('.  1".  Khakv,  M.A.,  of  the  Hritiiili  Mubcuiii. 

In  (WO  I'artH. 

Contents  of  Part  I:  Karlii'st  Traers  of  Man;  tlip 
Second  Stone  A),'e;  the  (irowth  of  I.anniianes ; 
I'amilies  of  I.ani'uai'es ;  the  Nations  of  the  Old 
World  ;  Karly  Social  l.ile  ;  the  Vill,i;,'c  (dmmunity. 
Contents  of  I'arl  II:  Kelly  ion  ;  Aryan  Ueliyion  ; 
iIk-  Other  Worlil  ;  Mythoiciu'ies  and  Folk  'Pali's; 
Picture  Writing  ;  Phonetic  Writing  ;  Comlusion. 

No.  40.  The  DlMrnmoM  ol'  Ifloiiiory.    My 

Til.   kiHoi,      (Traiislaled    frmn   the    French   l)y 
J.  l''rr/.(iKhAi.ii.) 

Contents:— Memory  as  n  niolo(,'ical  Fact  ;  Gen- 
eral Amnesia;  Parti, d  Amnesia;  Kxaltation  of 
Memory,  or  llyperr-nesia  ;  Conclusion. 

No.  47.  The  <  hlldliood  of  Hollaloiia. 

My  KowAKi)  Ci.uDO,  I'.K.A.S. 

Contents  ^in  part):  — l.eeends  of  the  Past  ahaut 
Creation  ;  C  reation  as  lolil  by  Science  ;  Legends 
of  the  Past  about  Mankind  ;  Ancient  and  Modern 
Hindu  Reli^'ions,  etc.,  etc. 

No.  48.  Lire  III  Nature.  Pv  Jami'.s  Himon, 
Author    of  •■  Man   itui  Ins  Dwelliii;^  Place." 

C.ntents  (IP  partK  -  I'unciion  ,■  !.ivin«  I'orms  ; 
Is  Life  I'niversal  ?  Nutrition  ;  Nature  and  Man  ; 
the  Life  of  Man,  etc.,  etc, 

No.  40.  The  Sun:  -its  Constinitlon:  Its  Phe- 
nomena' its  (  (indition.  Hy  N^iiian  P.  C.mk, 
LL.I).,  Jud>{e  of  the  Ninth  Ju  .icial  Circuit  of 
Indiana. 

Contents  (in  part)  ;-  The  Sun's  Atmosphere  ;  the 
Chromosphere;  the  PhotMspherc  ;  PrmUutlon  ol' 
the  Sun's  Spots  ;  the  t>iiestion  of  tiic  iCxtinction  of 
the  Sun,  etc.,  etc. 

Num.  .'iO  and  .'•1.  HIoiio)'  and  the  ITIeeh* 
aiilMin  ol*  Kxcliaii^^o.    Hy  Proi.  W.  Sian- 

I.KY  JliVO.Ss,  F.  K.S. 

Contents  (in  parti :— Phe  I  unctions  of  Money; 
F-arly  History  of  .Monty;  the  .Metals  as  .Monev  ; 
Principles  of'Cireulation  ;  Promissory  Notes  ;  tin 
Banking  System;  ih.:  Cleariiit,'  House;  Ouantily 
of  .Money  needed  by  a  N:ainn,  etc.,  etc. 

No.  52.  The  DimeuMeN  of  the  IVIII.    Pv 

'Pii.  Rnior.    (.Pranslatcd  Iroin  the  F'rench  by/. 
Fitzgerald.) 

Contents :— The  Question  Stated;  Impairment 
of  the  Will — L.tck  of  Imfiiilsion  — I'.xcess  of  Impul- 
sion ;  Impairment  of  V<.'luntary  attention  ;  Caprice  ; 
F-xtinction  of  the  Will  ;  Coiulusidii. 

No.  53.  Aiiiinul  .liitoiiintiDiii,  and  Other 
Essays.     Hy  Prof.  T.  H.  Hi  xi.kv,  F.K.S. 

Contents :— .Animal  Automatism;  Science  and 
Culture;  Elementary  Instruction  in  Physiolojry  ; 
the  Border  Territory  between  Animals  and  Plants  ; 
Universities,  .Actual  and  Ideal. 

No.    54.    The   Birth    and    Growth   of 

I?Iyth.    By  F'dwako  Ci.oDi),  F".R..\.S. 

Contents  (in  part) : — Nature  as  viewed  by  Primi- 
tive Man  ;  Sun  and  Moon  in  Mytholoy-v  ;  the  Hindu 
Sun  and  Cloud  Myth  ;  Uemonology  ;  Beast  F'ables  ; 
Totemism,  etc.,  etc. 

No.  55.  The  Selcntlflc  BaftlitoriTIoralH, 

and     Other     F;ssays.     By    William     Kini.uo.n 
CUFFORD,  F.R.S. 

Contents-— Scientific  Basis  of  Morals;  Right  and 
Wrong ;  the  Ethics  of  Belief ;  the  Ethics  of  Re- 
MgioD, 


No*.  CO  and  5T.  Ilinalonai  A  P«7* 
t-lioluuleul  Mtiidy.  Ry  Iamk-.  .>ullv. 
('on'cnts:  Ptie  Sdnly  o|  Ill'isi  .n  ;  Cl.i'^siliotuin 
I'l  lllusiuiiH;  Illusions  of  Percept  ion  |  I  >rciiiait , 
IlliiMoii.  of  Intros|u'ttlon  ;  Other  ^.)u.iM-l'resenlt«- 
tive  Illusions;  lllusiiins  of  Memory;  lllusiunn  of 
Itellel. 

NoH,  5K  and  50  nwo  •Intible  niiml)ers,  ;<>  cento 
e.iciii   TileOrlulnol'tliieelrM.    ByCiiAKLKs 

l)\NH  IN. 

•«•  Till*  is  Unrwin's  famous  work  tom|Jete, 
with  Index  and  ^,'lM,^arv. 

No.  (to.  The  <  hiidhood  of  the  World. 

Ily  F-iin  AKi>  t.  I  Mim,  i'.i<..\.«). 

Contents  iln  parli:  -Man's  I'lrst  W.inls,  Mann 
F'lrst  TiM'ls.  iMri.  I)\Vellin;;s,  I'se  nf  Metals;  Lan- 
i;iiaj,'i-,  WriluiL',  ('ciuntiiiL'.  Myth',  almiil  S.un  ^.nd 
Aloi'ii,  Star-..  I'.(lips<s;  I(,c,is  abniii  the  Soul,  Ik- 
llef  ill  '.Vitihi  r.ili,  I'eliclilMii,  Idolatry,  etc.,  etc. 

By  Rich- 


No.  Ul.  ITIlNeeiiuiiouiiM  I<:m«u)n. 

AUIl   A.    pKiil   Kin. 

Contents:-  Strange  Coincidences;  Cnlncidence* 
and       Superstitions;       ('■ambllnif      Siiperstition«>  ■, 
l.earnliit;  Lan«uai;es;  Str.m>;e  Sea-('ie,iiuies ;  the 
<  irJKJn  of  Whales  ;  Pr;iyer  and  Wtiitlur. 
No.  01  (Iloidil"    number,    t.  cenlsV  The    He* 

lluioiiNurtlie  Aiieieiit  World. 

Ciiiit'iits:  Kell;;|i)iis  nf  the  .Am  ii  iit  p"(.,'yptiau>., 
;iiu  lent  Iranians,  .Vssyrl.ms.  H.ibylni'.i.ois,  aiu  lenl 
S.iiiskrillc  Indi:ins,  Phcenu  i.iiis.  Car'h.ii,'iiiians, 
I'',iius.aiis,  ancient  dreeks  iind  ;ini  lent  Unmans. 

No.     0:i.     ProicreMKlve     iTIorallty.      Pv 

'liMiNM  ,  h'nwi  i;i.,    F'.S..'\.,   Prc.-.i(kia  of    Corpus 

Cliri.'.ti  Collejjc,  Oxford. 

Conunts:-  The  Sanctions  of  Conduct;  the 
Mnr.d  S.ini  tinii,  or  Moral  Seiitinuiu  ;  .Xii.ilysi^ 
•  md  I'orin.itinn  of  the  Moral  Sentiuviu  ;  tlir  Mnr.d 
'Pe^t  ;  l'x,tm)iles  of  the  practical  ai'plicalioiis  o( 
the  Moral  'lest. 

No.  04.  The  Dlntrlbiitlon  of  Mf'e.    fiy 

All  KKi)   Rlsm-.i.  Wai  lac  k  and  W.   P.   rni>i-.Lli':N 

l>M-.K. 

Contents  (in  parti  :-Cieo^'raphical  Distribution 
of  I. and  Animals;  iJisirjInitlon  of  Marine  .Aid, 
mals  ;  Relations  of  .Marine  with  'Perreslriiil  /oolojf- 
kal  Rc^finiis ;  iJistribution  of  V'eKi't.ilile  Lift-, 
Nnrtlicrii,  Southern.  'I  rn|)ical  Flora,  etc.,  etc. 

No.  05.  t'oiidltioiiH  «it  iTIeiital  Dovcl* 
opilieilt*  and  (Jihcr  Ls;)  ,ys.  iiy  William 
KiNoiio.s  CLiiinun,  F'.R.S. 

Contents  :— Conditions  of  Mental  Development; 
■Mins    and     Instruments    of    Sclciitilii      I'liouyht; 
.Atoms  ;  'Phc  l'"lrst  :iml  the  Last  Cat,islro|i|ie. 
No.  00.  Teehiileal  ICdiieatioii,  ,  \u\  other 

I'.nsays.     Hy  PiinMAsll    IIi.miv.  F.k..^. 

Contents: — Teclinlc:il  I"liic;illon  ;  The  Connec- 
tion of  the  HiolD^ical  Sciencss  with  .Medicine; 
Joseph  Priestley;  On  Sensation  and  the  Ciiiiy  of 
Structure  of  the  Senslferous  Or).;;iiis  ;  fin  ''ert.iin 
Frrors  respecllnt;  the  Structure  of  the  lleait  at- 
tributed to  .Aristotle. 

No.  07.  The  Ulaek  Death  ;  An  ac(  rxuit  h{ 

the  (jreat    Pestlieiice  of  the   nth    Century.     Hy 

J.  F.  C.  HtcKi  K.  M.I). 

Contents  :--Gcneral  Observations;  the  Di-iease  ; 
Causes- Spread,  Mortality;  Moral  IClTccts  ;  Pliysi- 
'ians ;  Appendix. 

No.  08  (Speci.ll  Number,  in  crntsi.  Tlireo 
1C!«lia)'A,  viz.:  Laws,  and  the  Order  of  tin  if 
liis.iivervj  Origin  of  Animal  Worship;  Pnlili- 
c;d  F'etichism.     Hy  Hei.iuk  r  Si'i:nci;k. 

No.    09  (Double  Number,    ;o  cents).    IfelJell" 

ImIII  :  A  Contribution  to  Anthropolo^'v  :Liid  tin.- 

Hismry  of  Reliijion.     Hv  I'"n  i  '  Scm'I  i;i  o,  Ph  I). 

Translated   from  the  Germ;in  by  J.   I'"itzL,'<  raid, 

M.A. 

Contents;— The  Mind  of  the  Sa^acre ;  Rrl.iiion 
between  the  Savage  Mind  and  iis  Object ;  1".  ti  fa- 
ism  .'US  a  Religion  ;  Various  Objects  c>f  I'etlch  Wor- 
ship:—The  Highest  Grade  of  F-ctichism;  Aim  of 
F-etichism, 


No.  70.    KMMayH,  Speculative  and  Prae* 

ticat.    l>y  ili.Kiii'.i<i  MBNLKK, 

Coiui-iUs:  Specialized  Administration;  "The 
Collcclivi'  Wisduni  ;  "  Morals  and  Moral  Senti- 
ments; Kfasoiis  (ur  Dissentiii)^  from  tlie  Pliilos- 
opliy  of  Coinle  ;  Wliat  is  Klettncity  ? 

No.  71.  Aiithrupolu^y.  Lly  Daniul  Wil- 
son. LL.O. 

Contents  :— Scope  of  the  Science  :  Man's  I'lacc  in 
Nature;  (Jrit^in  of  Man;  Races  of  Mankind;  An- 
ti(}uity  of  Man      Langua){e  ;  Uevelopnieni  of  Civ- 
iii/.ation. 
Sit.   7i.     Tlio  Dan<-iiii;   IVlania  of  the 

iUitiaiu  Aa,>'i».     Hy  J.  K.  C.  Hi-.cKiiK,  M.I>. 

Contents  (in  ixirt):  -The  IJancini;  Mania  in  (Jer- 
manyanl  Uie  Ncilierlands  ;  The  iJancinj,'  Mania  in 
Italy;    i'lvj  l^anciiij^  Mania  in  Abyssinia. 
Nu.   T.i,    Involution   111  Illtttory^  Lan- 
;;iia:;'4',  Ulld  .Seizure.     Lectures  delivered  at 
tlie  l.oiulo.i  Crystal  I'alace  School   of  Art,  Sci- 
ence, and  1-iteralure. 

Contents:— The  Principle  of  Causal  Evolution; 
Scicntilic  Study  of  Geofjrapliy  ;  Hereditary  Ten- 
dencies ;  Vicissitudes  of  the  Kn;;lish  Language. 

NoM.  74,  75,  7G,  77.  The  DcHceat  of 
nun,  and  Seleetluii  la  Uolatlon  to 
8ex.    liy  CiiAuLics  Dakwi.s. 

•«*  Price,  Parts  74,  75,  jfu  fifteen  cents  each  ; 

Nn.  77  (double  number),  thirty  cents;    the  entire 

work, !  "veniy-five  cents. 

No.  78.    Historical  Sketch  of  the  Dis- 
tribution or  Land  In  J<:iis£land.      By 
Prof.    VV'.M.   Li.oYU    BiKKiiKCK,   Cambridge   Uni- 
versity. 
Contents:— Anglo-Saxon  Agriculture;  Origin  of 

Land    Properties ;    Saxon    Law  of  Succession   to 

Land  ;   Norman  Law  of  Succession  ;   Inclosure  of 

Waste  Lands,  etc. 

No.  7».  S(-I<>utlflc  Aspects  ofSonie  Fa- 
miliar TIllllgM.  liy  VV.  M.  Williams, 
F.k.S.,  F.C.S. 

Contents:— Social  Benefits  of  Paraffin;  Forma- 
tion of  Coal ;  ('hemistry  of  Hog  Reclamation  ;  The 
Coloring  of  Green  Tea;  "Iron  Filings"  in  Tea; 
Origin  of  Soap  ;  Action  of  Frost  on  IJiiildiiig  Ma- 
terials, etc.  ;  l'"ire-Clay  and  .Vnthracile  ;  Rumloril's 
Cooking-Stoves;  Stove-heated  Rooms;  Domestic 
Ventilation. 

No.  8U.    Chat- IcH  Darwin :  His  Life  and 

Work.     Hy  Gkani  Allk.n.     (.Double  Number, 
30  cents.) 

No.  81.  The  JHystcry  of  :»Iatter.  Also 
The  PhlloMophy  ol'  l^jiioraiice.    By  J. 

Ali.assun    I'lcni.N. 

No.  8'i.     Illusions  of  the   Sciimcm  and 
Other  Kssiiys.     liy  Rh.haki')  A.  I'holiok. 
Conleius:— Illusions  of  the  Senses;   .■Kniinals  of 

the  Present  and  the  Past  ;  Life  in  Other  Worlds  ; 

Earlhquiikes  ;  Our  Dual   Mrain  ;  A  New  "^lar  in  a 

Star    Cloud  :    Monster    Sea-Serpents ;    Origin    of 

Comets. 

No.  83.  Proflt-^hnrin^r  Belwccn  La- 
bor and  <'HpUal.     By  Si-i.n.ia  Tavi.ok. 

CtmtciUs :— Priilit-Shaviiig  in  the  Maison  Le- 
claire  ;  Profit-Sharing  iti  lii.liistrv  :  Profit-Sharing 
IQ  the  Paris-Orleans  K.R.  Co.  ;  Prolit-Sharing  in 
Agriculture;  An  Irish  F.xperiment  ;  Protit-Shar- 
in;;  in  Distributive  Enterpri.se. 


No.   84.  Studies  of  Animated  Nature. 

liy  W.  S.  Dallas. 

Contents:  —  Hats;     Dragon-Flies;    The    Glow- 
Worm  and  other  I'hosphorescent  Animals;  Minute    ' 
Organisms. 

No.  85.    The  Essential  Nature  of  Re- 

ll{{lUII.      liy  J.   Al.LA.N.so.N  I'lClO.N. 

Contents:  Religion  and  Freedom  of  Thought; 
Evolution  of  Religion;  Fetichism;  Nature-Wor- 
ship; Prophetic  Religions;  Religious  Dogma;  The 
Future  of  Religion. 

No.   8«.   The    IJiiMecn    Vnlversc.     Also 
The  Philosophy  of  the  Jfure  Science; 

liy  VVm.  Ki.NoDcj.N  L.L11- 101:11,  F.R.S. 

Contents:— The  Unseen  L'niverse;  Philosophy  of 
the  Pure  Sciences  ;  Statement  of  the  jjuestion  ; 
Knowledge  and  Feeling;  Postulates  of  the  Science 
of  Space;  The  Universal  Statements  of  .Antliinetic. 
No.  87.  The  Morphine  Habit  (^Tlor- 
phinoniunia.)  With  Four  uilier 
liCCturcs.    By  Pkof  H.  Hall,  M.D. 

Contents  :— General  Description  of  Morphino- 
mania:  Effects  of  the  Abuse  of  Morphine;  Effects 
of  Abstinence;  The  Borderland  of  Insanity,  l'rt>- 
longed  Dreams  ;  Cerebral  Dualism  ;  Insanity  in 
Twins. 

No.  88.    Science  anci  Crime,  and  other 

Fssays.     ByANi<Kiiw  VVii.so.s,  !•  .K.h.f-;. 

Contents: — Science  and  Crime;  Earliest  known 
Life-Relic;  About  Kangaroos;  On  Giants;  'I  lie 
Polity  of  a  Pond;  Skates  and  Rays;  Leaves. 

No.  89.     The  Genesis  of  Science.     Bjr 

HeRUKKT  SrENLEK. 

To  which  is  added  :  The  Coming  of  Age  of  "  The 
Origin  of  Species'"  By  T.  H.  Huxley. 

No.  90.  Notes  on  Earthquakes:  with 
other  Essays.     Hy  Rkhakd  A.  Pkoctok. 

Contents  :— Notes  on  Earthquakes  ;  Photo^jraph- 
ing  Fifteen  Million  Stars;  Story  of  tlie  Moon; 
The  Earth's  Past ;  Story  of  the  Earth  ;  Falls  of 
Niagara;  The  Unknowable  ;  Sun-Worship  ;  Her- 
bert Spencer  on  Priesthoods  ;  Star  of  Retblehem 
and  a  BibleCoiuet ;  An  Historical  Puzzle  ;  Galileo, 
Darwin,  and  the  Pope ;  Science  and  Politics ; 
Parents  and  Children. 

No.    91.    TheRlseofFnlversltles.    By 

S.  S.  Laurie,  LL.D     (Double  number,  30  cents.) 

Contents  :— Romano-Hellenic  Schools;  Influence 
of  Christianity  on  Education;  Charlemagne  and 
the  Ninth  Century;  The  First  Universities;  Saler 
num  School:  University  of  N.iples;  of  Bologna: 
of  Paris,  Constitution  of  Universities;  Ciraduaiion; 
Oxford  and  Cambridge;  University  of  Prague, 
etc. 

No.  92.  Formation  of  Vesrtalile 
Mould  Throii^li  the  .\ctioiiol'  tvarlli- 
Worins,  with  Observations  on  their 
Habits.  By  Charles  Dauwin.  (.Double  Num- 
ber, 30  cents.) 

No.  93.  Sclentlflc  Methods  of  Capital 
Piinlshinent.  Hy  J  Moii.sr  Bi.ever,  M.D. 
(Price  ten  cents.) 

Contents  •  General  Review  of  the  Subject ; 
Death  by  Hanging-  hy  I'Mectricity;  by  Subcut;i- 
neous  Injection  of  Morphine;  by  Chloroform:  by 
Prussic  Acid;  Objections.  Appendi.x  .  Infliction 
of  the  Death  Penalty,  By  Park  lienjamin. 


m 


>C| 


PI 


Sent  post-fr<:e  on  receipt  of  price. 

J.  FITZGERALD,  PUBLISHER, 

24  East  4th  St.,  NEW  YORK. 


,jT-'7l 


.  Nature. 

The    Glow.      I 
aU;  Minute 

re  of  Ke- 
if Thought; 
vature-Wor- 
Joxraa;  The 

rue.  Also, 
I  Sfleii«-e ; 


hilosophy  of 
c  (Juestion  ; 
I  ihc  Science 
:  Arithmetic. 

bit  (ITIor« 
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(  Morphino- 

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sanity,  I'ro- 

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ioiice.     By 

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Hhdci'ok. 

Phot'i'^raph- 
f  the  Moon; 
rth  ;  Falls  of 
;)rship  ;  Her- 
jf  Bethlehem 
'.zle  ;  (lalilco, 
nd    Politics  ; 

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graduation; 

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011  their 

Rouble  Num- 


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CROSBY'S 

VITALIZED  PHOSPHITE 


•     COMPOSED 
OFTHB 

NERVE-GIVING 

PRINCIPLES 
OP':rHB 


■*  *  ■  »  » 


rvcwl 


This  is  a  standard  jjrepnralioii  «fitif  all  physicians  who  treat  ne 
mental  disorders.  It  is  iii||  A  ifcret,  the  formula  is  on  every  label, 
careful  chemical  composition^^  been, superintended  for  twelve  years 
Professor  of  Materia  Medica,  and  its  correct  analysis  vouched  for  by  a 
lessor  of  Chemistry.  Physicians  alone  have  prescribed  over  a  million 
ties,  curing  nervous  derangements  and  debility. 

It  aids  in  the  bodily,  ami^onderfully  in  the  mental,  growth  of  chil 
Xt  cures  f  retf ulness  and  slee|^ssness.  * 

By  its  special  tonic  effect  upon  the  nerves,  and  its  vitalizing  infli 
on  the  blood  of  young  persons,  it  brightens  the  eyes  and  gives  good  col 
the  lips  ;  it  ensures  a  soft,  smooth  skin,  glossy  hair  and  handsome  nai 
that  these  become  an  inheritance  in  later  years.  It  feeds  the  brain 
thus  strengthens  the  intellect,  so  that  study  and  deep  mental  application 
be  a  pleasure,  not  a  toil. 

It  is  used  as  a  special  brain  tonic  by  all  the  best  minds  of  this  and 
countries. 

It  strengthens  the  powers  of  digestion,tis-a  positive  cure  for  t 
sweats,  and  prevents  consumption. 

"  It  amplifies  bodily  and  mental  powers  to  the  present  generatior 
•proves  the  survival  of  the  fittest,'  to  the  next." 

"There  is  no  other  Vital  Phosphite ;  none  Aat  is  extracted  from 
fVfetable  and  animal  tissues." 

Send  for  Circular. 


F.  CROSBY  CO.. 

56  West   25TH   Street,    New  York 


fl    125.    H=iC.    1 


le  present  generatior 
at  is  extracted  from 


a3900^  0051 7  28  19b 


WHEAT  AND  i 


:ians  who  treat  nervoi 
la  is  on  every  label, 
ided  for  twelve  years 
l^sis  vouched  for  by  a 
cribed  over  a  million 

nental,  growth  of  chil 

and  its  vitalizing  infli 
es  and  gives  good  col 
lir  and  handsome  nai 
It  feeds  the  brain 
;ep  mental  application 

est  minds  of  this  arid 

a  positive  cure  for  t 


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